Has Anyone created an App to keep track of coaching clients

Has Anyone created an App to keep track of coaching clients

Has anyone ever created an app to keep track of clients, either professional or in my business, for coaching. Most apps on the market seemed to be a massive overkill and designed to do everything. I just need something that creates client records for goals, notes and session information and allows bookings to integrate with Zoho calendar. 

Has anyone had success with this?