MTL Labu

The Pentecostal Wave

About this app

MTL Labu is an offline-first hymn songbook for fast reading on your phone.

Read hymns anytime:
- Offline storage on your device
- Clean lyrics reader with font size control and immersive mode
- Favorites (pin hymns you use often)
- Search across titles, songbook, category/occasion, and lyrics

Helpful reader tools:
- Share hymn text to other apps
- Related and matching hymns (same occasion/language, or matching songbook + number)
- Optional audio link support (Google Drive or direct MP3/WAV link) when available
- Optional YouTube link support (embedded, floating mini player, or open externally)

Admin publishing (optional):
- Admin login (Google + Firebase) unlocks hymn editor and upload to Firebase Realtime Database
- Edit filters (languages, categories, songbooks) and publish updates for readers

What’s new

* Added Sync button on Hymns, Admin Hymn List, and More menu.
* Added Sign in / Sign out options in the More menu.
* Swap tool now allows selecting only 2 hymns (auto-clears if a 3rd is selected).
* Added Undo for the last Swap or Rearrange operation.
* Fixed duplicate/extra hymn count issue during Swap/Rearrange by using atomic Firebase moves.
* Transfer tool now assigns the lowest available hymn number starting from 1 in the target songbook (prevents number conflicts)