Paid app on computer (via google play store) but installed on phone as 'unknown sources' (not via the play store) I just paid for 2 apps on my computer logging into the play store.
But I installed them on my phone as .APKs so how to have the free versions turn into paid?
Answering this myself.
I downloaded the respective PRO versions. I guess these versions have access to the "play store receipts" and so both apps booted the Pro versions properly.