Most companies spend more time every week for checking the timesheets to know how much time each user has spent on each project and then create invoices every time when they need to bill to the clients.
Once you have integrated the Mobile Time Tracker application with the Xero app, and have set the scheduler for generating invoices in the Mobile Time Tracker application. The invoices get generated automatically in the Xero app under invoices, by considering the hours worked by the users. Accounts people can re-check the invoices if necessary and bill it to the clients.
As the hours worked details are accurate, the invoices get generated with exact hours worked by users on a particular project, and it is easy to bill to the clients. This way you save a lot of time spent generating the invoices manually in your org.