A free app for Android, by SmartApps38.
The free app, PDF Repair Tool, is a utility that can be used to repair PDFs that have been corrupted or are otherwise unreadable.
It is very easy to use and works with a wide variety of files.
You will not need to download any other tools or configure any settings. All you need to do is install the app and then run it.
The app will then search for all the PDFs that you have in your device and will show you the ones that are available. You can then choose to download the ones that you want to fix.
The app will then begin the repair process and will check all the PDFs for any issues.