In a nutshell: MAU = Monthly Active Users.
Every time your app gets installed, we generate a new unique ID for the app on the device. This ID gets passed on to our servers once we receive a request for translations from the app on the device. If this ID wasn’t previously registered in the current month (it’s a new app install), then we increase your MAU counter by one.
In other words, the counter is increased the first time the ID is seen in the current month. If that ID was already registered (seen by our system), your MAU counter won’t be changed.
At the beginning of each month the MAU counter will be reset.
If your QA team does a lot of testing, and the app is getting installed/uninstalled many times as the new builds arrive, then each new installation of the app will increase the counter.
Once your MAU reaches 90% then we will give you orange warning.
Once your MAU goes over 100% then we will give you a red warning and your users won't be able to download new translations from us :(