Originally Posted by SecUpwN
How come you can't use it? Would be awesome if HushSMS could decide which API to use depending on the calling app used in the ROM. In a future update?
It's because you need to declare a shared user (android.uid.system, or at least android.uid.phone). For this you must sign the app and install it as a system app. On devices with stock roms this would require to sign the app with the manufacturers key which is obviously impossible.
So this can only be done on devices whith custom roms. Additionally it would require me to use apis which are declared internal by google and since HushSMS is sold via the Google Play Store this might violate the TOS of Google.