Frequently asked questions

Currently sixteen Android apps — ExperimentApps Installer (installs and updates our apps, with every file verified), FileDeck (a file explorer with network locations), Keystroke Sender (scripted keystrokes to a PC), LED Ticker (a scrolling LED sign across several phones), Light Editor (a text editor with syntax highlighting and Markdown preview), Media Viewer (an offline photo and video viewer), NetScope (a local network analyzer), NetWarden (a local VPN firewall and traffic monitor), Off (one tap to lock your phone), Offline Recorder (recording and offline speech-to-text), PDF Viewer (a private PDF viewer that also opens Office files), Pocket NAS (your phone as a network drive), SFTP Studio (an SFTP/FTP/SSH server and client), SyncDeck (folder sync and backup), Tag Actions (NFC tags that run actions) and Tether (remote control over VNC and SSH) — fifteen offline games: 2048, Chess Puzzles, FreeCell, Hex Marbles, Hitori, Mahjong, Make Ten, Marble Maze, Nonogram, Number Match, Solitaire, Spider Solitaire, Sudoku, Tilt Pop and TriPeaks — and two Windows applications: AI OS Controller (an AI assistant that diagnoses your PC, with your approval) and Disk Toolkit (find duplicate files across your drives and clean up safely).

All our Android apps need Android 8.0 (Oreo) or newer, except ExperimentApps Installer and PDF Viewer, which need Android 9 or newer, and Media Viewer and NetWarden, which need Android 10 or newer. Keystroke Sender's Cable mode also needs USB Host / OTG support, Pocket NAS needs a USB-C port with OTG support if you want to share a USB drive, Tag Actions needs a phone with NFC, and LED Ticker's multi-screen display needs NFC and Android 12 or newer. AI OS Controller and Disk Toolkit are for Windows 10 / 11 with the .NET 9 Runtime.

They are experimental hobby projects, distributed directly as APK files from this site (and our Windows applications as zip files). Each app page has a download section with install instructions.

Download the APK, open it, and when prompted allow your browser or file manager to "install unknown apps". Then tap Install. Full step-by-step instructions are in the download section of each app page, for example Keystroke Sender. This is a standard Android feature, and you can switch the permission back off afterwards. Once you have ExperimentApps Installer, it can install and update all our other apps for you.

Each download section shows the file size and its SHA-256 fingerprint. Calculate the SHA-256 of the file you downloaded (for example with certutil -hashfile file.apk SHA256 — or the name of the zip file — on Windows or shasum -a 256 file.apk on macOS/Linux) and compare it with the value on the page.

Before anything is installed, the APK must come over HTTPS from experimentapps.com, match the SHA-256 published on its app page, carry a signature Android accepts, be signed with our own certificate for that app, and be signed by the same key as the last time. If any check fails, the download is deleted. See ExperimentApps Installer.

Android never lets an app install other apps without your approval. Tap Open settings, turn on Allow from this source and come back; you only need to do this once, and you can turn it off again at any time. Android still asks you to confirm every install and update.

The installer only installs Android apps and games. AI OS Controller and Disk Toolkit are downloaded on a PC from their own pages.

WebDAV (for example Pocket NAS, Nextcloud, Synology or QNAP), SFTP (for example SFTP Studio, Linux, macOS or a web host), FTP / FTPS and SMB (Windows shares, Samba and most NAS devices). For SMB, enter the name of the share. See Add a network location.

No, it's optional. With it, FileDeck can show and manage every file like a computer's file manager. Without it, use Places › Add a folder to give access to any folder you pick (also on a USB drive), which needs no permission at all.

That's by design: FileDeck never runs in the background. Running copies pause when you leave the app and continue as soon as you return. For long copies, keep FileDeck on screen.

Opening a network file downloads a temporary copy. Changes made to that copy in another app are not uploaded back automatically; copy the file back to the NAS with Copy and Paste.

Yes, since FileDeck 1.2.0. When an app asks for a file (for example Attach in your e-mail app or Upload on a web page), open the menu of Android's file picker and choose FileDeck. You can then pick files from your phone, SD card, USB drive and your network locations. See Pick files for other apps.

It turns your Android device into a virtual keyboard and mouse. You write a script on your phone, connect it to a computer over a CH9329 USB cable or an InputStick Bluetooth dongle, and the app "types" your script into that computer as if it came from a real keyboard.

No. The computer sees a standard USB or Bluetooth keyboard/mouse, so no drivers or software are required on the PC. It works with practically any operating system that accepts a keyboard.

One of two things: a CH9329 USB-to-serial adapter (for Cable mode, using your Android device's USB Host / OTG support), or an InputStick Bluetooth dongle (for wireless Dongle mode). Without one of these, the app cannot reach a PC.

Make sure you selected Cable mode in Settings, then tap Refresh and grant USB permission when Android asks. Check that your cabling and adapter support USB Host / OTG. Turning on Debug Mode in Settings shows detailed logs that can help pinpoint the issue.

Enable Windows Mode (CR+LF) in Settings. This sends both a carriage return and a line feed at the end of each line, which many Windows terminals expect.

Yes. Save them as macros using the Save button, and open them again from the Macros screen. You can also generate sample macros to see how the scripting syntax works.

No. One phone works as a scrolling LED sign on its own. Two to eight phones side by side make one long display; for that every phone needs NFC and Android 12 or newer.

Turn on NFC and Bluetooth on both phones, allow Nearby devices when asked, and keep LED Ticker on screen on both. Hold the phones back to back where the NFC antennas are (usually the middle of the back) for a second; slide them slowly if nothing happens. See Connect phones.

No. They were created with AI to show how the multi-screen display can be used, as noted below the photos.

Light Editor is offered for text files and common script and configuration types (such as .json, .xml, .ps1, .sh, .md, .yml). Some file managers report unusual files as a generic type; on Android 12 and newer the app also recognizes many of those by their extension. Otherwise, open the file from within the app with File › Open.

Usually not. When the app goes to the background with unsaved changes, the text is kept as a draft and comes back the next time you start Light Editor. Only Exit followed by Don't save removes it. See Drafts.

Open a photo in a file manager, pick Media Viewer and tap Always; do the same for a video. If Android doesn't ask, clear the default of your current gallery app first. See Make Media Viewer your default viewer for the steps per phone brand.

Android 11 and later doesn't let apps pick the Download folder itself (or the root of a storage) with the folder picker. Choose a folder inside Download, or turn on All files access in Media Viewer's Settings.

The folder was renamed, moved or deleted, or the SD card was removed. Tap the collection and choose the folder again.

No. Delete removes the file permanently (after you confirm); there is no recycle bin. Keep a backup of photos and videos that matter to you — SyncDeck can help with that.

Android 10 and newer no longer let apps read the table of MAC addresses on the network, so NetScope can't show the MAC address or manufacturer of other devices. Many phones and laptops also use randomized MAC addresses.

No, that's correct. Devices on your own network are one hop away, and switches, access points and repeaters are invisible to traceroute. The Route page explains each result.

Android 17 blocks apps from the local network until you allow it. Tap Allow in the banner at the top of NetScope; if you denied it permanently, the button opens the app's settings.

Only networks and devices you own or are explicitly allowed to analyze. Scanning a network at work, school or on public Wi-Fi without permission may break its rules or the law.

No. The VPN is local: it runs entirely on your phone, and traffic goes straight from your phone to its destination. NetWarden never contacts a server of its own.

NetWarden doesn't decrypt anything, so for HTTPS it only sees the domain name. Set Android's Private DNS to Off or Automatic and turn on Block QUIC to see and block domains reliably.

No. Android allows only one active VPN at a time.

On our own Android phones the first unlock after Off asks for the PIN code. Some phones behave differently and may still allow fingerprint or face unlock; the phone is locked either way. Android's built-in Lockdown option in the power menu always asks for the PIN.

Off is a device admin app. First turn off its access in Settings › Security › Device admin apps › Off (search Settings for "device admin"), then uninstall it.

Yes. It uses the offline Vosk engine. You download a free speech model once per language with your browser and import the .zip in the app's Settings. See Add speech models.

Tap Allow background activity in Settings. On Samsung, Xiaomi and Huawei phones, also set Offline Recorder to Unrestricted in Android's battery settings.

That's by design: PDF Viewer has no file picker and keeps no history. Tap the file in your Files app, e-mail or browser downloads and choose Open with › PDF Viewer, or share it to PDF Viewer. See Open a document.

Search, text selection, links and passwords use Android's own PDF engine, which offers them on Android 15 and newer, and on Android 12–14 after a recent Google Play system update. On older devices you can still read, zoom, share and print.

No. PDF Viewer has no internet access at all. Office files are converted by the app's own code on your device, macros are never run, and the temporary copies are deleted when you close the viewer.

No. Pocket NAS uses WebDAV, which Windows, macOS and Linux support out of the box, and it has a file manager that works in any web browser. On iPhone/iPad use Safari or a free WebDAV app. See Connecting from your devices.

Android has no separate "local network" permission: the Internet permission is needed to open any network port, even one that only listens on your home Wi-Fi. Pocket NAS never connects to the internet itself and, by default, refuses every connection from outside your local network.

Windows limits WebDAV files to 50 MB by default. The Pocket NAS page shows a one-line registry command that raises the limit to 4 GB; restart the computer afterwards. For even bigger files, use the browser or a client such as WinSCP or Cyberduck.

Check that both devices are on the same network (guest Wi-Fi often blocks devices from seeing each other), that the NAS is started, and that you copied the address including the port (for example :8080). After 8 wrong passwords a device is blocked for 5 minutes.

Exclude Pocket NAS from battery optimization (there is a button on the Status tab). Some brands (Samsung, Xiaomi, Huawei, OnePlus, Oppo) have extra "app sleep" settings: set Pocket NAS to Unrestricted there.

Never open a port in your router for it. For safe remote access, install a VPN such as Tailscale on the phone and your computer; Pocket NAS accepts Tailscale addresses while Local network only stays on.

Any SFTP program: FileZilla, WinSCP, Cyberduck, a terminal (sftp -P 2222 user@address), FileDeck or another SFTP Studio. The Server page shows the address, user name and password; the SFTP Studio page has step-by-step instructions.

Ports below 1024 need administrator rights on computers and are not allowed on Android at all, so SFTP Studio uses 2222 for SFTP/SSH and 2121 for FTP. You can change them in Settings.

To share other folders, such as Download, DCIM, an SD card or a USB drive, allow All files access when the Shares page asks for it.

Allow notifications, and in Settings › Background and power exclude SFTP Studio from battery optimization. On Samsung, Xiaomi, Huawei, OnePlus or Oppo phones, also set it to Unrestricted in the brand's own battery settings.

Echo makes an exact copy (files deleted at the source are deleted in the destination too), Synchronize keeps two places the same in both directions, and Contribute copies new and changed files but never deletes anything. See Three ways to sync.

With Wait for the destination on (the default), the sync simply waits and runs as soon as the drive is connected, without filling the history with errors.

SyncDeck has several safeguards: deleted and replaced files are kept for 30 days, a safety stop halts a folder when more than half its files would be deleted, and a folder that can't be found is never treated as empty. Use Preview to see what a sync would change. See How your files are protected.

Tap the button in Settings to allow SyncDeck to run in the background without battery restrictions. Without it, Android may delay background work. Android 15 and newer also limit background syncs to about 6 hours a day; longer syncs continue later automatically.

All 13.56 MHz NFC tags: NTAG, MIFARE, ICODE, most NFC stickers and many library and transit cards. Phones can't read 125 kHz key fobs, UHF clothing labels or store anti-theft tags. Bank cards, passports and phones often report a new random ID on every scan, so they can't be used as tags.

Turn on Run actions in the background in Settings. Then scan an unknown tag with the app closed: if you see "Unknown tag …", background scanning works. If not, check that NFC is on, the screen is on and unlocked, and that no other NFC app handles tags. On Xiaomi (HyperOS/MIUI) and similar phones, enable Start via NFC in the app info permissions. See Good to know.

Because each action needs something different: SMS for text messages, location for sharing your location, Bluetooth for connecting devices, and so on. Android only asks you for a permission when you add an action that needs it. The Tag Actions page explains every permission.

Newer Android versions no longer let ordinary apps switch these settings. In that case the action opens the right settings screen for you. Airplane mode and location can switch directly if you grant an extra permission from a computer with ADB.

Android only reads NFC with the screen on. You can turn off "Require device unlock for NFC" in Android's NFC settings, but then anyone with your phone can trigger your tag actions while it is locked.

A VNC server for the screen (for example TightVNC or UltraVNC on Windows, Screen Sharing on macOS) and/or an SSH server for a terminal (OpenSSH Server on Windows gives a PowerShell prompt, Remote Login on macOS, openssh-server on Linux). See Prepare the computer.

No. Use VNC to see and control the screen, or SSH for PowerShell and the command line.

Never open VNC or SSH ports in your router. Use a VPN such as Tailscale or WireGuard on your phone and computer, and connect through it.

Not by default: every command is shown to you first. In Auto-run safe commands mode, read-only commands run straight away, but risky ones (deleting, registry, services, installs…) still ask. The risk check is a safety net, not a sandbox, so always read what you approve.

The program is free. Google Gemini and Anthropic Claude need your own API key, and those providers may charge for API use depending on your plan. A local model with Ollama is completely free.

Install the free .NET 9 Runtime (Windows x64) from dotnet.microsoft.com, then start the program again. See What you need.

No. The application never deletes anything. You mark the copies you don't need, and it writes a PowerShell script. Run that script with -WhatIf first to see what would happen, and with -UseRecycleBin to delete to the Recycle Bin. See Getting started.

Yes. Create an index of each disk once, then compare the index files together. The delete script checks that the right disk is connected before it removes anything from it.

Yes, when the index is split into parts. Progress is saved after every part, also after a crash or reboot; resume it on the Pending jobs tab. Checksums make indexing much slower, but are strongly recommended before you delete anything.

No. All our games work fully offline and request no permissions at all — they have no technical ability to go online.

In Clear mode it shows whether the board can still be cleared completely (green), is proven impossible (red), or is uncertain (orange). In Refill mode it shows whether you are on track for the target score. Tap the dot for details. See How to play.

Yes. Undo and redo are unlimited, and in Clear mode you can tap the red dot and choose Back to green.

Hex Marbles is played against computer players, with three strengths: Easy, Normal and Hard. The Big battle game type has three computer opponents, each with its own style.

No. The app has no background services at all. Computer players pause as soon as the game leaves the screen and continue when you return.

Most of our games have a built-in solver. In the card games (Solitaire, Spider, FreeCell, TriPeaks), Mahjong and Number Match, green means the game can still be won and red means it is proven that it can't — use Undo. In Chess Puzzles, green means you can still force mate in the moves you have left; in Tilt Pop it shows whether the screen can still be emptied (Clear) or the target reached (Moves). In Sudoku, Hitori and Nonogram, red means one of your marks is wrong. In 2048 it shows how much room you have left. Tap the lamp for details.

Every new deal or puzzle is checked by the built-in solver, except on the levels that are random by design (Hard in Solitaire, Master in Mahjong, Expert in Number Match). You can still play yourself into a dead end — that's what the lamp warns you about. Every Marble Maze has exactly one route between any two spots, so it can always be solved, and every Chess Puzzles puzzle is proven to have one winning first move.

Yes. The game numbers (1 to 1,000,000) match classic Windows FreeCell exactly. Try game #11982, the most famous unwinnable deal.

Only for tilt controls. The motion sensor needs no permission and is only on while you play. Without a sensor (some tablets), or when you'd rather not turn the phone, choose Swipe or Buttons under Settings › Controls.

No. There is no analytics, no telemetry, no account and no login with us. Keystroke Sender, LED Ticker, Light Editor, Media Viewer, Off, Offline Recorder, PDF Viewer and all our games don't even request internet access, and Disk Toolkit has no network code at all, so they cannot send anything off your device. ExperimentApps Installer only connects to experimentapps.com, Pocket NAS and SFTP Studio only serve files on your local network to devices you allow, FileDeck and SyncDeck only connect to the servers you add, NetScope only talks to the devices you enter and your network's own DNS server, Tether only connects to the computers you add, NetWarden only passes on the traffic of your other apps through its local VPN, Tag Actions only sends what you set up yourself (a text to the contact you chose, a web request to the address you entered), and AI OS Controller only sends your questions and masked command output to the AI provider you choose (or nothing at all with a local Ollama model). Nothing is ever sent to us.

No. The apps are not web apps and use no cookies. This website sets no cookies or trackers either.

Completely free, with no ads and no in-app purchases. We never ask for money. The only possible cost: if you use Gemini or Claude in AI OS Controller, that provider may charge for its API.

The apps are provided "as is", for learning and experimentation, with no warranty. Only use Keystroke Sender on computers you own or are explicitly authorised to operate, always keep a backup of files you share with Pocket NAS or SFTP Studio or manage with FileDeck and SyncDeck, only scan networks you own or may analyze with NetScope, set up Tag Actions with care (for example, only share someone's location with their knowledge), only control computers with Tether or AI OS Controller that you own or may manage, read every command before you approve it in AI OS Controller, ask for consent before recording people with Offline Recorder, and always run the delete script of Disk Toolkit with -WhatIf first. You are solely responsible for how you use the apps. Please read the full Privacy Statement & Disclaimer before use.

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