Collection of Mobile and web, do I need to close and open the mobile app

I have tests that needs to be done on the mobile app, I open the app in one test but then when I finish a serie of test cases I need to do some verification in a web portal and then go back to the mobile app. Between the collections of mobile -web-mobile do I need to do a close of the mobile app and then a start of the mobile app again? Do I need to re-initialize all my global variables?