From your client's profile, you'll see their "to-do list compliance". Clients will see this stat on their profile as well. This stat tracks a combination of their Habits, Surveys, Progress photos, etc. and then provides you with a % based on the number of tasks they've completed.

If your client completes 2/4 habits, 1/2 surveys, and 3/4 progress photos, they would have a compliance score of 7/10 (70%).