Designing a Fast OTP Receiver on Android Without Background Battery Drain

One of the biggest pitfalls of mobile utility apps is aggressive background polling that drains user battery and triggers OS warnings.

In Mailfo, an Android temporary email app, our challenge was ensuring sub-second OTP delivery while maintaining near-zero standby battery consumption.

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Strategy: Adaptive Polling & Local Room Cache

1. Active Foreground State: While the user is actively waiting on the inbox screen, the app uses short-interval reactive updates.
2. Background Transition: The moment the app is backgrounded, continuous polling is throttled immediately to conserve battery.
3. Local Persistence: Data fetched is instantly cached in Room SQLite, ensuring that when the user switches back, the data is immediately available without a loading spinner.

Result? A fast, reliable, battery-friendly tool for daily signups and developer testing.

👉 Check out Mailfo on Google Play Store

Website: https://mailfo.pages.dev/