I as a professional QA Engineer, always provide integration testing with multiple platforms and cross device testing to make sure clients apps are stable
The latest client i worked with had an app that was running on web, on android devices and on iOS. Then it had to be integrated with a second app that was on a kiosk were it was running a desktop app.
Rigorous testing was done in order to make sure there aren't any differences between the platforms that could generate bugs
