The Experience section, accessible via the dropdown arrow in the individual client window, shows the client's class attendance and bookings.
Tapping in the window that opens, allows you to access the client's booking information. The dates that are faded are classes that are in the past. Clicking on a date takes you to that class.
The "Load all past bookings" button allows you to access every booking of that client.
At the bottom of the window is where you can rate the Pilates experience of that client on different equipment. To rate their experience, click on one of the greyed out buttons.
Here all all the main help categories in the Appilates user manual.