I built Blood Donation Tracker as a simple, private way to keep donation dates on a Garmin watch without an account, phone connection or server.
It can log today or an earlier donation, keeps the last 24 dates plus a lifetime total, and shows a countdown to a reminder date using the interval you select. Duplicate and future-date protection are included, and everything stays in on-device storage.
Important: the date is a personal reminder only, not a medical eligibility decision. Rules vary by country, donation type and individual health, so users should always follow their blood center and qualified medical advice.
I am the developer. The app is completely free and requests zero permissions.
Store: apps.garmin.com/.../e8ea0594-bbaa-4236-a2e0-05b2f2efad29