Within these limitations at form design and API level all business logic should work.
A mobile client works offline, so the first time it must do a synchronization with the server, this will be automatically called when the client starts up.It will then also ask for credentials first if the solution requires authentications.
With Servoy 7.4 this automatic initial synchronization can be avoided if the first form doesn't have a datasource, so it doesn't need data. This way you can control the sync and login completely in your solution. Be aware no initial login will be shown either, if you want to make sure a login form is always presented you have to make your own (without datasource) and show this as first form, calling security.authenticate with the result for future use.
Servoy mobile assumes the same user is using the same or his own device.
If this is not the case, i.e. any user can use any device, you will have to make sure your own login form is present and shown each time the application opens.This is possible by making it the first form (without datasource), you might also want to clear the local storage to make sure no one sees other people data.