This software is well designed and highly customizable
LearnUpon - Create and deliver online courses to your employees, clients and partners. LearnUpon is the fastest growing learning management system in the world.
Angle 2 Mockups - A giant Sketch Library for creating app presentations
Respondus - Respondus is the name of one of the best assessment programs for managing learning management systems.
Velvet UI Kit - Cozy iOS UI Kit designed for Sketch ๐ธ
Adit Testdesk - Create, run, and grade all sorts of tests automatically!
Avataaars - Mix and match avatars with a Sketch library