I'm going to start this review out with a gigantic disclaimer: I used PlayStation Mobile on a rooted Nexus 7, per Artem's instructions, hardware that it wasn't technically designed for. The service should run on just about any (rooted) Android device, as well as natively on most recent Sony phones and tablets. At least some of the games in the store are also available on the PlayStation Vita. Other Android users are having trouble (even I had to flash to a stock, rooted backup), so stability and performance may certainly have been somewhat off while I used the service.
Even so, PlayStation Mobile, or at least the Android version, is awful.