DNScapy - DNScapy is a DNS tunneling tool. The code is very light and written in Python.
UXTesting - Discover how your mobile users feel
Map Pod - Quick, easy real-time location sharing for iOS
Startup Timelines - How the frontpages of famous startups changed over time
Blokada - The best ad blocker for Android. Free and open source.
Really Good UX - A library of screenshots for UX inspiration