Mockuuups Studio - Fast and easy way to create product mockups on macOS, Windows and Linux.
Gyroscope - Gyroscope is a personalized dashboard for tracking your life.
Mockup Generator - Create attractive product screenshots with just a few clicks
CareKit by Apple - Open source software framework for creating health apps
Previewed - Beautiful mockups & graphics for your next app
DNScapy - DNScapy is a DNS tunneling tool. The code is very light and written in Python.