We offer our self-serve clients a GDPR Addendum that - in turn - will protect them (as good as it can)
Furthermore; after extensive reviewing the GDPR we conclude that we are still comfortable collecting Device-ID’s and/or placing Cookies. Possibly more important; we are still (very) comfortable serving ads based on GPS coordinates AS LONG as the app in question informs their downloaders/users that GPS coordinates are collected.
Besides creating this addendum, we have found a way to map all apps that properly inform their downloaders/users about the commercial use of lat/long coordinates - which is in compliance with GDPR protocol.