Any good period tracking apps for preteens?

[SmeagolAteMyWombat]

My 11 y/o started her period. She's had it twice and we have been looking for an app to track them so she knows when it might come next. I used several different ones before my hysterectomy but the ones we downloaded to try won't let her sign up because of her age. Apparently she is not allowed to track her cycle on the ones we've looked at because she is not old enough!!! 🙄😬
Trust me, I would have preferred she waited to start having them but it is what it is.... me feeling old!!!

Clue? Just amend her DOB for the app.

Don't get her the app Flo, it asks about your sex life which I find annoying and intrusive

I 2nd clue, just change year of birth if it doesn’t let you register but it’s really sleek and simple to understand.
No giant pink flowers either

Another vote for clue. Easy to use.