I used part of the "Laundry App UI Kit Sketch Resource" design that was designed by Satheesh Kumar at: https://www.sketchappsources.com/free-source/3397-laundry-app-ui-kit-sketch-freebie-resource.html to create a quick prototype

Circular progress bar

A news app prototype with a reading percentage indicator upon scrolling. Includes variables that calculate the scroll position in % and update the loader fill percentage. Fill free to import!

Scrollable Landing Page Design from: https://www.sketchappsources.com/free-source/1975-key-t-one-page-website-template-sketch-freebie-resource.html Top Menu and Side Slider changes (State) depending on the scroll position with the use of variables

Form validation using variables and states