How does placer.ai get its data?

According to TC [0] placer.ai collects data from 40% of iPhone and 60% of Android users in the US via its SDK! How are they encouraging top apps to install their location tracking SDK? Is this some sort of hidden library that gets auto-included via something like CocoaPods [1]? Or maybe they partner with an ad platform and include their SDK as part of theirs? Still neither one of these really explain how they can have such high penetration.

[0] https://techcrunch.com/2021/04/27/location-data-analytics-startup-placer-ai-raises-50m-series-b/

[1] https://guides.cocoapods.org/using/the-podfile.html