Solved: Define backend language per each admin user in Magento
In Magento 18.104.22.168 a client has a multi language store set up and they would like me to give them a native language backend for every admin user. It was quite easy.
How to set up a preferred language for each Magento admin user:
1. Download the Aoe_BackendDefaultLanguage zip
2. Unzip and copy the app folder contents to your Magento's app folder
3. In Magento backend clear cache and rebuild
4. Go to System -> My Account in backend
5. You will see a new selection dropdown for your default backend language.
If this helps you, please do not hesitate to leave a reply or share, keeps me motivated. And big thanks to Daniel Zohm for the module!