iOS Design Kit - The newest library of native iOS templates
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
draw.io - Online diagramming application
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
iOS Design Course - The Complete iOS Design Course with Sketch from Bitfountain
LightShot - The fastest way to take a customizable screenshot.