Mozilla Stumbler promotes non-free services
Only a small amount of data collected with Mozilla Stumbler https://f-droid.org/repository/browse/?fdfilter=stumbler&fdid=org.mozilla.mozstumbler is free, i.e. the prosition of cell towers. The vast majority of data, namely the WiFi access point database, is proprietary. Scroll down https://location.services.mozilla.com/downloads to "WiFi Networks" where there is no data download, only a claim on why the data is proprietary.
As such, I believe Mozilla Stumbler should be tagged as "promotes non-free services".