2. Click the “Choose File” button and choose your apk file. Then, in the first text box, enter “.rar” (without quotes). After that, enter your desired name for your .rar archive and click the big “Rename!” button

3. Go to the folder where your .apk file was. You should see a .rar archive, named by the name you entered in Formatter. Extract it with your archive manager

How to repack .apk files:
1. Compress the extracted files in a .rar archive (compress them normally like any other archive)
2. Open Formatter
3. Choose the .rar archive you made a minute ago
4. Set the format to .apk
5. Set the name to whatever you want
6. Click the big “Rename!” button