Rift Shard Status
It's fairly straight forward; the Menu has 3 options: EU, US, and Settings - the first two change which region you're looking at, the third lets you change the default region, automatic update and notification options.
Long-press a server to set/unset it as your favourite (any number of servers can be set as favourites)
Favourite servers can be listed in the notification for quick access.
Most phones will need to enable the setting to keep it awake for background updates to work (when the screen is off), this may use extra battery.