Bluebox Security Scanner app checks if you are patched against the Android 'Master Key' exploit
Bluebox Security, the company that found the glaring Android vulnerability that can circumvent the app install verification on 99% of current handsets in circulation, now has an app for you to check whether your phone has been patched.
Google yesterday said that it has already plugged that hole, and Samsung is even shipping phones with the patch now, but if you want to check whether your handset has been updated with the patch, download the Bluebox Security Scanner from the link below.
HTC seems to have done it already on the One flagship, so if you get "Patch status: Patched" on your phone or tablet, all should be well with the world again.
source: Bluebox Security Scanner (Google Play)
Things that are NOT allowed: