In relation to a school project we're working on a mobile application for Android, we can't find out where it would be natural to keep our language modules.
We're thinking of either keeping the ressource files for every language locally on the cellphone hence keeping them close and available - or in our online database for saving space on the cellphone, but therefore requiring clients will need internet access to switch the language.
Thanks in advance!
For static content you should prefer to deliver them within your apk. How you already mentioned this make switching language more easy and this is the most natural way. Here some documentation about multi language support https://developer.android.com/training/basics/supporting-devices/languages.html
Saving space could be necessary but how many space takes each of your translations? Often it's better to use proguard to shrink your apk size.
For dynamic content like blog posts I would prefer an online database. Then you don't need new releases for updates.