Record football juggling exercises.
You can check your growth and practice pace with graphs and calendars.
Voice input is convenient.
"left foot 10 times"
"head 10 times"
You can talk and record.
If it is only numbers, recording is easy even if it is not voice, but only one foot, football juggling etc. can be easily input if you specify a title, such as lifting.
Since you can talk and record, even children can record it.