I’ve been working on a new Android app called Pocket25, and it’s finally ready to share.
Pocket25 turns your Android phone into a full-featured P25 digital trunking scanner using an inexpensive RTL-SDR dongle. It’s built on the DSD-Neo decoder, bringing the same class of P25 decoding you’d normally need a desktop PC for, straight to mobile.
If you’ve ever wanted to monitor modern public safety radio systems without carrying a laptop or a $500+ scanner, this is for you.
What Pocket25 does
Pocket25 is designed specifically for APCO P25 systems:
- Phase 1 (FDMA / C4FM) — fully supported
- Phase 2 (TDMA / QPSK) — currently in testing
- True trunk tracking — follows conversations across control channels so you don’t miss replies
Automatic system setup
Pocket25 integrates with the RadioReference database:
- Search your county or city
- Select the system
- Import and start listening
No manual frequency typing required.
Live signal data
While audio is playing, Pocket25 also shows what’s inside the digital signal:
- Talkgroup IDs, Radio IDs, and NAC
- WACN, System ID, Site ID, RFSS
- Encryption and emergency flags
You can actually see what’s happening on the network, not just hear it.
Filters and logs
- Whitelist or blacklist specific talkgroups
- Review call history and activity
- Manual tuning for conventional (non-trunked) channels
Hardware support
- Works with RTL-SDR dongles using a simple USB OTG cable
- No root required
- Built-in drivers for low-latency performance
- Can connect to remote rtl_tcp servers over a network
Under the hood
Pocket25 uses DSD-Neo and mbelib, giving you accurate, high-quality P25 decoding from well-established open-source code.
Source code
GitHub:
https://github.com/SarahRoseLives/Pocket25
App download
https://sarahsforge.dev/products/pocket25
Requirements
- Android 8.0 or newer
- RTL-SDR V3, V4, or compatible RTL2832U dongle
- USB OTG cable
Legal note: Pocket25 is intended for authorized radio monitoring only. Always follow local laws regarding radio interception and encryption.