Simple view pager indicator based on Jardson Almeida concept.
https://dribbble.com/shots/2429036-Page-Scrolling

Gradle

compile 'com.merhold.extensiblepageindicator:extensiblepageindicator:1.0.1'

Define view in xml layout

<com.merhold.extensiblepageindicator.ExtensiblePageIndicator
        android:id="@+id/flexibleIndicator"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:indicatorRadius="12dp"
        app:indicatorPadding="32dp"
        android:layout_marginBottom="80dp"
        android:layout_gravity="bottom" />

than init view pager object

ExtensiblePageIndicator extensiblePageIndicator = (ExtensiblePageIndicator) findViewById(R.id.flexibleIndicator);
extensiblePageIndicator.initViewPager(mViewPager);

Available attributes:

• indicatorRadius - circle radius
• indicatorPadding - space between the circles
• indicatorInactiveColor - rare circles color
• indicatorActiveColor - extensible circle color
• android:gravity - left, center or right

Extensible Page Indicator is published under the Apache 2.0 license.