While the app is a great way to play on the go some features are still only accessible from a desktop type connection.
If you don't have a pc you can switch your mobile device browser to desktop mode.
Select the menu in the lower right, then the settings gear, then scroll down for the switch to desktop button


To switch language servers from the main page you just select your flag in the upper right, and then any games you create or join will be in that language server. Once you have joined a game it will be playable from the app without changing language servers.
