Nifty - Manage projects, work, and communications in one place.
Sketch Repo - Collection of resources for anyone who uses Sketch
UnderPinned - One app to manage your projects from start to finish.
Plant - Version control app and plugin for Sketch
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Timeline for Sketch - Create beautiful timeline animations in Sketch