what is the other on my ipod touch

"Other" includes everything that is not audio, photos, apps, or books. It includes videos, messages, emails, app data, your Camera Roll, and iOS itself. The only way to prevent it from increasing is to not use your iPod Touch.

Settings > General > Usage > Storage shows you how much data each app uses.

Sure, first try restoring the iPod Touch from a previous backup.

If that does not work, restore as new will.

Read: iTunes: Restoring iOS software

Follow the instructions carefully - most importantly these notes:

Before restoring:

• Verify that you are using the latest version of iTunes.
• Back up your device.
• Transfer and sync content to your computer.

Restoring it is really the only way to eliminate corrupt data, which could be the reason for excessive app data storage.

Why are you reluctant to do it?

Have you ruled out all other possible reasons? Remember "other" includes videos, messages, emails, and your Camera Roll in addition to potentially corrupt app data.

Backing it up will ensure you can undo whatever can go wrong. You should be doing that periodically anyway.

Just read the instructions - click the links to learn how to do it:

Before restoring:

• Verify that you are using the latest version of iTunes.
• Back up your device.
• Transfer and sync content to your computer.