Set up is quick and easy, once the Mobile Time Tracker application is integrated with the Xero app, the invoices can be generated automatically with some setup in Salesforce.
To integrate the Xero app Mobile Time Tracker application,
The oAuth for the Mobile Time Tracker must be processed before the Xero integration. Follow the instructions here if the oAuth for the Mobile Time Tracker is not done earlier.
Click the TT setup tab and click on Connect to Xero button. You see the message as "Mobile Time Tracker for Xero want to access" and shows the company name with Allow Access button. Click the Allow Access button. Now you see the message as "Thankyou, you are all set". Close this Tab
Go to the TTSetup tab again in Salesforce, Select the Scheduler sync frequency and select the Sobject, the same object which users track time in your org. Then click the Get Contact and Generate Invoices button and click the Save button.
Settings to be done on the Xero application
Login to the Xero app, click the settings button, and click the Connected Apps tab, you see the connected apps list. Click the "connect" button which is next to Mobile Time Tracker application.
Now the Xero app is integrated with the Mobile Time Tracker application and Invoices can be generated automatically by setting up a scheduler in the org.
Once the Xero app is integrated with the Mobile Time Tracker application, please create a schedulers for generating invoices in the Xero app and a scheduler for syncing the Xero contacts to Salesforce.