Train in order, not by weekday.

Rotation for iPhone

List the sessions you rotate. Rotation shows the one that's next and asks once a day whether you went.

Coming soon to the App Store
Check in Yes Up next
Order, not dates The next session follows the last one you did. Miss a day and nothing shifts.
Rest is never a failure Say no and the same session waits for tomorrow. Nothing breaks when you rest.
Stays on your iPhone No account and no tracking. Your rotation never leaves the phone.