I’m looking for some site/library/project with advanced custom Android controls? if you know one, are they free and open sourced?
Take a look at commonsguy github repository. You can find several quite interesting android components there, all with source code available under Apache License
android-arsenal.com has a few controls, utilities and scripts; it’s a mixed bag but it’s the closest thing I’ve seen to a controls website.
Been a while anyone posted on this thread.
I often refer http://www.androidviews.net/
Tons of free and open sourced custom controls.
You’ll love it.