I have created a simple to use plugin that you can add to your Appgini application that can help you change your Appgini generated application language easily. It presents you with a list of all the translated language files. Simply download the language's zip file and extract it inside your plugins folder in your Appgini application. That's it !!! you can now go to the Admin area and on the plugins menu, you will find the Language Plugin.
Download it here :https://github.com/ronniengoda/appgini-languages-translation