Mark a To Do as done from the Agenda
1.) To mark a To Do as done, swipe it to the left.
2.) Or Tap on the To Do and then tap on the checkmark to mark it as done. A filled checkmark mean the To Do has been marked done.
Mark a To Do as done from a Profile
Tap on the To Do in the To Do section of the profile.
And then mark it done or make other changes.