Amateur Radio logging that stays out of your way.
W4MSI Logger is a field-focused Amateur Radio logger for everyday QSOs, Parks on the Air (POTA), Tiles On The Air (TOTA), and simultaneous multi-program activations.
Current Android release: 1.7.9- General Amateur Radio log
- POTA activation and P2P logging
- TOTA activation and T2T logging
- Simultaneous TOTA + POTA sessions
- Multi-operator contact logging
- Offline callsign and POTA park data
- Downloadable offline maps
- GPS Journey Recording
- ADIF and GPX export
- Backup & Restore
- Local-first data storage
- No account or advertising
Built around real field operating workflows.
POTA Activations
Create single- or multi-park activations, log Park-to-Park contacts, track activation QSO count, search the offline parks database, and discover nearby active parks using GPS.
TOTA Activations
Create TOTA activations using 6-character Maidenhead tiles, select tiles by GPS or map, log Tile-to-Tile contacts, and optionally record a GPS Journey.
Multi-Program Sessions
Operate TOTA and POTA simultaneously from one logging screen while W4MSI Logger maintains separate program records for review and export.
Multi-Operator Contacts
Log several operators from the same exchange without re-entering shared reports, P2P parks, T2T tiles, band, mode, or frequency.
Offline Field Operation
Core logging works without internet access. Optional downloadable callsign data, worldwide POTA park data, and supported U.S. offline map packages extend field capability.
Journey & Mapping
Record TOTA Journeys in the background, monitor Inside/Outside tile status, receive boundary alerts, view routes, find parks, and select tiles or parks on the map.
General Log
Log everyday contacts outside an activation with callsign lookup, contact editing, and ADIF import/export.
ADIF & GPX Export
Save or share activation ADIF files and recorded Journey GPX files for compatible logging, activation, GPS, and mapping services.
Backup & Restore
Create portable backups containing settings, activations, QSOs, General Log contacts, linked session information, and Journey GPS points.
A clean interface designed for actual operating.
From choosing an activation program to finding a park, logging shared contacts, reviewing linked activations, and preparing exports, the workflow is built for quick use on a phone in the field.
Core logging works where the internet doesn't.
W4MSI Logger keeps core logging and activation functions local to the device, so QSOs and activations remain usable without cellular or Wi-Fi service.
Android users can optionally download an offline U.S. Amateur Radio callsign database, an offline worldwide POTA parks database, and supported U.S. offline map packages before heading into the field.
Recorded QSO information can include
- Contact, operator, and station callsigns
- Band, mode, and operating frequency
- RST sent and received
- Transmit power
- Local and UTC timestamps
- POTA park and Park-to-Park references
- TOTA tile and Tile-to-Tile information
- Saved callsign lookup information
- Multi-operator and multi-program linkage
Built by W4MSI.
W4MSI Logger is developed and published by W4MSI with an emphasis on practical Amateur Radio field operation and offline-capable workflows.
W4MSI Logger is an independent application and is not affiliated with or endorsed by Tiles On The Air (TOTA) or Parks on the Air (POTA).
W4MSI Logger for Android
Amateur Radio logging for the field.
Get it on Google Play