Q: How can I backup documents in NOTES and WRITE app

Hello armfisch,

I understand that you would like to back up your informations from within apps on your iPad. That is something that you can do with. 

Now with most apps, you should have a share option. With that option, you can email a copy of the information within to yourself. If you are using iCloud, that information is synced across devices, but you will still need to back them up. For the Notes app, you will have the same share options on iCloud.com or you can use the Notes app on your Mac to back them up. Take a look at the article below for more details.

Share from apps
http://help.apple.com/ipad/9/#/iPaddbe97ce5​

Archive or make copies of your iCloud data
https://support.apple.com/en-us/HT204055

Another option is to back this information up in iCloud or iTunes. Take a look at the next article that goes over how to back up your iPad.

How to back up your devices using iCloud or iTunes
https://support.apple.com/en-us/HT203977

Take care