On a Galaxy S3 with Android 4.1.2, I tried to use this to revert an app (Aldiko e-book reader 3.0.6 to 3.0.4). When clicking to revert, it immediately said "Complete" but did nothing - Aldiko was still version 3.0.6. I ended up just clicking the APK file directly & installing, which even told me that it would preserve program data, which it did. Opened Aldiko and program is now the old version. A) This program doesn't seem to work & B) There's no need to use it (at least in this case).