Official comment
As noted in our email response (please don't post to the forum and send an email at the same time):
You have two devices associated with your account and 5 shared with other users. Installations on the same device with the Google Play and APK variants of the app count as separate devices against your total. If you need to clear some up you will need to either remove access for the other users, upgrade your account to Elite to get more devices or reset your device list (which can only be done after 6 months).
Uninstalling the app from the device does not remove it from the list of devices that have access.