For a client to use the App you will need to add a client as a Professional (an individual staff member of a client).
Once you've created the professional, to get them onto the app;
Go to Logins
Search the Professional's details
Select the professional
Click "send professional details"
The main benefits of using the App is that Clients can;
request bookings that will feed directly to your allocations screen
directly appoint staff
view the status of current open bookings/cancel them/accept who is appointed
they can also view a full history of the last 100 shifts per client.
place restrictions or make requests for staff members they like
view/query/approve time sheets submitted by members on the app.
Here you can have the complete guide of Client App on the below link