Fastest way to reach me: email smandeel@gmail.com — RecallKit is built by one person, and every message is read.
RecallKit handles Anki 2.0, 2.1, and 2.1b (zstd) packages. If an import reports skipped cards, the summary tells you how many and why. If the file fails outright, email it to me (if you're comfortable) and I'll reproduce the issue directly.
On your device, and in your private iCloud database if you're signed into iCloud. Deleting the app deletes local data; iCloud data can be cleared from iOS Settings → Apple ID → iCloud.
Check Settings → Sync & Backup inside the app — it shows the live iCloud account and sync state. A pull-to-refresh on the Home screen forces a re-check. Both devices need the same Apple ID.
Forgot = Again, Struggled = Hard, Remembered = Good, Easy = Easy. The intervals shown under each button are the algorithm's real output for that card, not fixed steps.
Yes — Settings → FSRS Tuning lets you set your retention goal per deck and re-optimise all 19 parameters from your own review history once you have a few weeks of reviews.
Email smandeel@gmail.com with what you did, what you expected, and what happened instead. Screenshots help. If you're on the TestFlight beta, the built-in TestFlight feedback (screenshot → share → TestFlight) works too.