I used the Sketch "Delicious" free UI Kit for a food recipes app. It includes 11 pixel-perfect screens. I just added Proto.io interactions and created a great prototype! This Delicious UI Kit was designed by Robert Anitei Sketch source: https://www.sketchappsources.com/free-source/1765-delicious-ui-kit-sketch-freebie-resource.html

A halloween project i have put together using the Proto.io Halloween icon set: https://proto.io/freebies/free-halloween-icons/

A Picker selection navigates you to the screen selected. The project uses Variables and States and depending on the picker selection I change a button state to navigate you to the right screen.

3 different counters using variables 1. A standard counter 2. A counter from the number of seconds the user sets 3. A countdown

Netflix Desktop UI Sketch Resource Design: https://www.sketchappsources.com/free-source/3590-netflix-desktop-ui-sketch-freebie-resource.html

Using variables to change the opacity of items Design Downloaded from: https://www.sketchappsources.com/free-source/2567-chandelier-lighting-illustration-sketch-freebie-resource.html

I made this illusion based on the Tusi motion method, which takes his name from Nair al-Din Tusi, a Persian astronomer from the 13th century. The principle established by Tusi states that: If a circle with diameter A rotates on the inner boundary of a circle with diameter 2A, then a point on the circumference of the inner circle traces a straight line. As you can see, any ball in the inner circumference is following a perfect linear movement. This is created with 8 Containers where the balls move linear in a loop. The delay between balls must be always the same as the speed of the animation. An ease-in-out cubic-bezier(.4, 0, .6, 1) animation is required to get the circular shape.