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Show HN: Bingo Caller Pro – Offline 75/90 Ball Bingo Host

1 points by 1derfool ↗ HN
I built an offline-first bingo caller app for hosting 75-ball and 90-ball games without physical cages or printed boards.

It started as a simple number generator for family game nights, but evolved into a full hosting tool with:

Professional voice calling (multiple personalities)

TV/projector display mode

Digital player cards via QR

Hex-based number verification to reduce disputes

Rollback for incorrect calls

9 language support

The app works completely offline and uses a secure RNG. No tracking, no data collection.

Would love feedback on usability, performance, or feature ideas.

Google Play Store link: https://play.google.com/store/apps/details?id=com.bingosurf....

3 comments

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1derfool
Most bingo/tambola caller apps I found either required internet for ads, analytics, or remote syncing. For community halls and senior centers (where this is often used), connectivity is unreliable — and I didn’t want gameplay to depend on network state.

So the app:

Runs fully offline (no API calls during gameplay)

Uses a cryptographically secure RNG for number generation

Doesn’t collect personal data

Doesn’t require account creation

The hex verification system was added after running into disputes during larger games. Instead of manual checking, each card can be validated deterministically against the called sequence, which made competitive sessions much smoother.

If anyone is curious about implementation details (RNG choice, QR card generation approach, state handling, etc.), happy to go deeper.

Also very open to critique — especially around UX clarity for large-screen TV mode.

gus_massa
What is "Hex-based number verification"?