A recent XDA piece on turning an old Android phone into a dashboard diagnostic display landed for a lot of readers because the math is obvious: an old Snapdragon-class phone is a free Linux-class computer with a screen, sensors, a camera, and Wi-Fi. The eight apps to repurpose an old Android phone below cover the proven jobs, from a security camera that runs for years to an OBD-II car diagnostic display, a webcam for a desktop, and a household automation hub.
What to look for in a repurposing app
Five things matter:
- Standalone or paired. Some apps run as a single device; others need a host phone or PC to pair with.
- Background reliability. A repurposed phone runs unattended for weeks. The app needs to survive Android’s aggressive battery optimisation.
- Power and heat. Continuous use shortens battery life. Plan for a permanently plugged-in setup with a charge limit if the firmware supports it.
- Privacy. Cameras and microphones running 24x7 are a privacy risk. Pick apps with a clear data-handling policy and a local-first option.
- Free vs paid. Many of these apps are freemium. The premium tiers usually add cloud storage or extra streams.
Quick comparison
| App | Best for | Free plan | Local or cloud |
|---|---|---|---|
| AlfredCamera | Free home security camera | Yes | Cloud |
| Torque Pro | OBD-II car diagnostic dashboard | Paid | Local |
| DroidCam | Webcam for a desktop | Yes (with watermark) | Local |
| AutoBoy Dash Cam | Dashcam recorder | Yes | Local |
| AirDroid | Remote control and file transfer | Yes | Cloud relay |
| Tasker | Household automation hub | Paid | Local |
| VLC for Android | Media player and lightweight server | Yes | Local |
| RetroArch | Retro game console under the TV | Yes | Local |
The apps
1. AlfredCamera Home Security, the free camera
AlfredCamera Home Security turns the old phone into a baby monitor, pet cam, or doorbell-watcher with motion alerts pushed to your current phone. The free tier covers continuous live view, motion-triggered clips, and two-way audio. The companion app on the watcher phone signs in with the same account and you are running.
The Premium tier adds higher-resolution streams, longer cloud history, and a zoom feature that the free version compresses past usefulness.
Where it falls short: continuous use heats older phones. Cloud history caps tightly on the free tier.
Pricing:
- Free with optional cloud history.
- Paid: AlfredCamera Premium subscription.
Platforms: Android, iOS, web.
Bottom line: the right pick when you want a security camera tonight without buying hardware.
2. Torque Pro, the OBD-II car dashboard
Torque Pro is the long-running car diagnostic app that turns an old phone into a dashboard for any car with an OBD-II port and a cheap Bluetooth ELM327 adapter. The screen displays live readouts: speed, RPM, coolant temperature, fuel economy, error codes. The customisable dashboards mean you can build an instrument cluster that reads exactly the metrics you want.
It is the app behind most XDA-style “I turned my old phone into a car dashboard” stories.
Where it falls short: a Bluetooth OBD-II adapter is a separate purchase. Some cars need a specific adapter chipset for full PID coverage.
Pricing:
- Paid: one-off Pro purchase.
- Torque Lite: free, limited.
Platforms: Android.
Bottom line: the right pick when the old phone is going on a car dashboard.
3. DroidCam, the desktop webcam
DroidCam turns an Android phone into a wireless webcam for Windows, macOS, or Linux. The phone’s camera streams over Wi-Fi or USB to a small host app on the desktop, and the host exposes it as a standard webcam to Zoom, OBS, Discord, and the rest. The image quality on a recent Android camera is significantly better than most laptop webcams.
The free tier ships at 720p with a small watermark on the host display only. The paid upgrade unlocks 1080p, no watermark, and rotation lock.
Where it falls short: the free version downsamples to 480p in some configurations. The host app is required on the desktop.
Pricing:
- Free with limited resolution.
- Paid: DroidCam Pro for full resolution.
Platforms: Android, iOS, Windows, macOS, Linux.
Download: Download
Bottom line: the right pick when an old phone with a good camera replaces a bad laptop webcam.
4. AutoBoy Dash Cam, the dashcam
AutoBoy Dash Cam records continuously while clipped to a windscreen mount, with G-sensor auto-clip retention on impact and loop recording so storage never fills. The Pro version adds GPS overlay, longer parking mode, and the more aggressive clip retention setting that matters in an accident.
The format works because dashcams are a perfect fit for an old phone: a single-purpose recorder bolted to a mount that does not need a sim.
Where it falls short: the lens position depends on the phone and the mount. Old phones with weak rear cameras record dim footage at night.
Pricing:
- Free.
- Paid: AutoBoy Pro for extra features.
Platforms: Android.
Bottom line: the right pick when the old phone is going in a car as a dashcam.
5. AirDroid, remote control and file transfer
AirDroid turns the old phone into a remote-accessible device from a desktop browser or another phone. Move files in either direction, mirror the screen, send and receive SMS through the desktop, and run the camera as a remote viewfinder. Pair it with a permanently mounted phone and you have a remote sensor pod with a camera.
The free tier is generous; AirDroid Premium raises bandwidth caps and unlocks remote camera over cellular.
Where it falls short: cloud relay routes your traffic through AirDroid servers on cellular. Bandwidth caps tighten over time on the free tier.
Pricing:
- Free with caps.
- Paid: AirDroid Premium subscription.
Platforms: Android, iOS, Windows, macOS, web.
Download: Download
Bottom line: the right pick when the old phone needs to be reachable from anywhere.
6. Tasker, the household automation hub
Tasker is the long-running Android automation app that turns the old phone into a programmable hub for a small household. Triggers fire on time, location, network, sensor, or accessibility events, and actions span notifications, scripts, HTTP calls to home automation systems, Bluetooth pairings, and dozens of plug-ins. Pair it with Home Assistant or MQTT and the old phone becomes a tiny edge controller.
The community plug-ins (AutoVoice, AutoNotification, AutoApps suite) extend it into voice commands and inter-app integrations.
Where it falls short: the learning curve is real. The first few profiles take longer than expected.
Pricing:
- Paid: one-off purchase, ongoing free updates.
Platforms: Android.
Bottom line: the right pick when the old phone is going to live as part of a smart-home setup.
7. VLC for Android, media player and lightweight server
VLC for Android plays anything you can throw at it and exposes the phone’s library over a small built-in HTTP server. Mounted near a TV or a stereo, the old phone becomes a Bluetooth-connected media player for the household, with the file browser handling local SD card content, network shares, and DLNA sources. Headless playback through Bluetooth speakers works without leaving the file browser.
The app is open-source and free, with no in-app purchases at all.
Where it falls short: the streaming server is intentionally minimal. Not a Plex replacement.
Pricing:
- Free, open source.
Platforms: Android, iOS, Windows, macOS, Linux, Apple TV, Android TV.
Bottom line: the right pick when the old phone is going to drive a Bluetooth speaker or a TV.
8. RetroArch, the under-the-TV console
RetroArch turns a wired-to-TV old phone into a handheld retro console that takes a Bluetooth gamepad. Casting the display to a TV through Chromecast or HDMI works once and then runs forever. Per-system cores cover NES through PSP, save states are shared with desktop builds, and the libretro gallery scrapes box art for a console-feel front end.
It is the right closing pick because the average old Android phone is more than enough hardware for the entire pre-PS2 console catalogue.
Where it falls short: ROM legality is on you to manage. First-time setup of cores and shaders takes patience.
Pricing:
- Free, open source.
Platforms: Android, iOS (sideload), Windows, macOS, Linux.
Download: Download
Bottom line: the right pick when the old phone is going to live as a retro console under the TV.
How to pick the right one
If you want a free security camera tonight, install AlfredCamera.
If the old phone is going on a car dashboard, install Torque Pro with a Bluetooth OBD-II adapter.
If you want a better webcam on your desktop, install DroidCam.
If the old phone is going on the windscreen, install AutoBoy Dash Cam.
If the old phone needs to be reachable remotely, install AirDroid.
If the old phone is becoming part of a smart-home setup, install Tasker.
If the old phone is driving a TV or stereo, install VLC.
If the old phone is going under the TV as a retro console, install RetroArch.
FAQ
Is it safe to leave an old Android phone plugged in continuously?
Yes, with two caveats. Use the original or a high-quality charger, and check whether your phone supports a charge limit (Samsung, OnePlus, and Sony have it built in; others rely on apps). Keep the phone in a ventilated location away from heat sources.
Will an unsupported old Android phone still work for these jobs?
Yes for most of the list. AlfredCamera, AutoBoy, DroidCam, VLC, and RetroArch all run on older Android versions. AirDroid, Tasker, and Torque Pro support a wide range of releases. Update the apps from a trusted store rather than the device updater if the phone is no longer receiving system updates.
Should I factory-reset the old phone before repurposing it?
Yes. Reset, log in with a fresh account if needed, and only install the apps you need for the new job. This is both a privacy step and a performance step.
How do I prevent Android from killing background services on the old phone?
Disable battery optimisation per app, lock the app in recents, and (for Samsung, Xiaomi, OnePlus, Huawei) disable any vendor-specific power saving for the apps in question. For long-running services, enabling autostart in the device manufacturer’s settings is often required.
Are these apps safe for an unmaintained old Android phone?
Strip the device down to only the apps you actually use, install via Aptoide, F-Droid, or Google Play, and avoid signing into accounts that hold sensitive data. Treat the device as a dedicated appliance.
