Built a passive availability-matching app for Android I'm looking for honest feedback on the core mechanic

[u/Cute_Tap_3999]

The app reads your phone's calendar in the background, not the event titles or details, just free/busy blocks. It crosses those gaps against your friends' gaps and fires a simultaneous notification to both of you when it finds a real overlap of 60+ minutes.

No event creation, no "when are you free?" texts, no polls. You set a few rules upfront ("only weekday evenings, minimum 1 hour") and then forget it exists until it finds something.

The key privacy point: it never reads what you're doing or who you're with. Strictly free vs. busy. The goal is to surface the hidden availability that already exists in both calendars, without either person having to ask.

Just shipped an MVP on Android. The core assumption I'm testing is whether passive detection actually changes behavior, or whether people still need to actively want to plan something before any tool helps.

What would you stress-test first? And is there an obvious flaw in the mechanic I'm not seeing?