Bots UI Kit - Fully customizable Sketch UI Kit for Messenger Platform
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
Now UI Kit - A beautiful Bootstrap 4 UI kit. Yours free.
Craftwork - A collection of User Interface resources made by Craftwork
Infinity Dashboard - A beautiful way to keep track of anything you want 📊
Rodman Mobile UI Kit - Premium colorful iOS templates designed for Sketch App