Tower Collector is an app to help contribute mobile tower data to Mozilla Location Services and OpenCellID, so that its open to all instead of a few large companies. Both of them are open source projects.
This data can be used for estimating location without GPS for example.
Fdroid link
If you use an online service to upload which towers you see, and get an approximate location as a response, then yes, it could be just ad bad from a privacy perspective. What these open databases allow is the possibility to download the whole tower database to your device, and then do the lookups locally.
oh yeah, i guess using Google location services is the same as sharing this with Mozilla or something, and Mozilla isn't Google