The last one I tried ran so hot and drained the battery in an hour. I think it must have been trying to mine on my phone! ...I just watch preev.com on my phone.
Just don't mix wallets and fishy bitcoin apps. I wouldn't go as far as to suggest to have a dedicated phone for your self-compiled and reviewed android wallet yet but this day will come soon. If some minor developer of angry birds can sneak in a 2kB snippet that empties 10,000,000 wallets at a snap, this evil guy will do it. I mean even if he gets caught, he might have a higher cause to do so and the money will never find its way back to the owners.
A bitcoin hater could even send the money to /dev/null
Edit: Wonder what he would get prosecuted for in such a case