1. When you first log in to the app it will sync the user's data from the org, downloading everything the user will need to work offline including Service Appointment and Work Order Details. This process can take several minutes or seconds depending on the amount of information that has been configured to sync. 

2. When the minimum level of information has been synced, you can optionally start using the app while rest of the syncing continues in the background. To do so, select the button Start Using the App

If you dismiss the Syncing Progress screen early via the Start Using the App button, UI performance may be slightly degraded until syncing completes, due to the processing occurring in the background. 

3. Once syncing has completed, a green banner will appear on the screen for a few seconds. 

For more on how to configure what is synced to the Axsy Field Service Mobile App, please see this article: Flexible Sync