UPDATE: In Flinto for Mac 2.2, we released native shapes, so this is now much easier. More here – https://www.youtube.com/watch?v=WuXAau5_034&list=PL8r3cIb8Ca8-tmfjmra-yKsCHvIq08Qy3&index=2
Use the behavior designer in Flinto for Mac to create a circular progress indicator. I included my setup in Sketch all well in this tutorial.
Get the source file here: https://dribbble.com/shots/3053981-Circular-Progress-Bar