TrackViewIndicator

demo_apk

you can use this lib like:

TrackPageIndicator trackPageIndicator = (TrackPageIndicator)findViewById(R.id.indicator);
trackPageIndicator.setViewPager(viewPager, new ArrayList<IGetSnapshot>());

IGetSnapshot is a interface:

public interface IGetSnapshot{
        View getOrgSnapshot();  //return the original view.
        void getAftSnapshot(View orgView);  //the view that will change by swipe the viewpager
    }

Gradle

compile 'andy.ayaseruri.trackpageindicator:lib:1.0.0'

Maven

<groupId>andy.ayaseruri.trackpageindicator</groupId>
<artifactId>lib</artifactId>
<version>1.0.0</version>

thanks to

张鸿洋的博客