Be able to set a different language than english when the device is using a not translated language of the app

[caos30]

I've android setted up to use catalan language, but (by now) the app doesn't have this language translation (i've translated just now on weblate.org), and then the app use the english translation by default... when i would prefer spanish instead, which it already exists as translation. Other people maybe prefer other already translated languages: french, german, portuguese, etc... all them already translated.

It would be great that the user could choose on the settings area of the app the language to use :-)

Cheers!! Sergi