Add item to a list in a SharePoint hosted app from another SharePoint hosted app

Question

I have two SharePoint hosted apps - say SPApp1 and SPApp2. SPApp2 has a list TestList in appweb(NOT the hostweb). I want to add an item to that TestList from SPApp1. I will click a button from SPApp1 and it will add an item to TestList in SPApp2. First of all, is this even possible? If yes, how might one go about this?

Any suggestions, tips are appreciated.

Thanks!