Filling the screen area with a solid white color which value makes up the percentage is an expression controlled by a simple slider fx. The goal was to end up with simple, lite and nice donut chart.
Dribbble - Animation Home [Gif] by Jordi Verdu / pinned by TriggerNews app
Currently browsing 20 Incredible Mobile UI Animations in GIFs for your design inspiration
Gif - Search Responsive by Agence Me (via Barthélémy Chalvet). Cool animated presentation of the app UI design.
Response Animation by Denys Basnikov