Ran across this today. Google has indexed the 100 most widely used commercial SDKs as a reference. Mildly interesting, possibly helpful.
Google Play SDK Index | Android Developers
Google Play SDK Index provides insights and usage data for popular commercial SDKs on Google Play so you can make informed decisions about whether an SDK is right for your business and your users. Find over 100 of the most widely used commercial SDKs and insights about each one.