First off, I am really sad about the state of Android & iOS platform support in UE4. Long story short, the BP implementation of IAPs (and ads, for that matter) is horrendous. The docs are missing and the “Read in app purchase information” method did not even work until I had to inject 3 extra lines of java code into the engine (using 4.10).
Now, I am not here to whine around. I have one particular problem: when the game starts, I would like to make sure the user has access to all the IAP products which he already purchased on his Google/iOS account. In Google Play ref (http://developer.android.com/google/play/billing/billing_reference.html) there is a getPurchases() method. In Unreal, there is nothing. This is terrible, and basically we can’t release our app without that functionality (what if the user reinstalls the app on his other device - he will have to make all the purchases again. At least the game would be trying to do that). I am trying to figure out how to implement it in c++ on my own, so if anyone has a working or at least WIP code/plugin here - I would appreciate it.