If I erase all content and settings and i have an app thats no longer on the app store, will i be able to get it back through the backup on my computer?
iPod touch, iOS 8.1.3
Yes if it is in a computer file backup.
Why not do this before erasing the iPod:
every time my iPod syncs with the computer does that mean all my iPod files are in a computer file backup?
It usually transfer iTunes purchases to the computer but not always. You can manually do that.
When you sync iTunes creates a backup but the backup does not included synced media like apps and music. For what the backup includes see:
reset ipod
