Here are our favorite apps to pair with UX Power Tools.
The is the most comprehensive and detailed icon set that exists. There are over 25,000 icons, all in a cohesive style. They have an amazing desktop app for searching, building sets, and creating icon sprites for you. Incredible.
Auto Layout by Anima
The best plugin for speeding up your layout in Sketch. It does small things well like stacking UI elements in containers to automatically space them based on set padding values. But it also does more impressive things like making your design file responsive.