Since it's probably even easier to track your habits by using a single guugle account which allows them to offer their real customers (adwords purchasers) deliciously personalised advertising, the android ecosystem seems to be built around users putting all their eggs (store purchases) into one basket ("sign in with YOUR ACCOUNT"). From my experience I have never seen an app complain about me using it on any compatible device which is connected to my the relevant g account. I wonder if developers are even allowed to set up their own click wrap license terms that show up only AFTER the purchase of the app. Like the one solid Explorer introduced a while back. It was way after my two hour refund window had ended that I first was shown it, and of course I didn't read it so I can claim to be in good faith about whatever is in it. Short story long: Introducing additional terms for the use of already purchased apps is likely to go afoul of mandatory EU consumer right rules and thus are unenforceable in court.