iMazing - iMazing lets you transfer music, files, messages, apps and more from any iPhone, iPad, or iPod to a computer, Mac or PC. Manage and backup your iOS device simply without iTunes. (was DiskAid)
Documents by Readdle - A central hub for all your files.
iExplorer - iExplorer lets you easily transfer music, playlists, text messages, files and more from any iPhone, iPod, or iPad to a Mac or Windows computer and iTunes.
FE File Explorer - The one-stop files solution
Decipher Backup Repair - Fix corrupt and buggy iPhone backups so that you can restore your backup in iTunes!
GoodReader - With GoodReader on your iPhone, iPod Touch or iPad, you can read virtually anything, anywhere.