SmallDevTools - Handy developer tools with a delightful interface
Whisper.sh - Whisper is the best place to express yourself online. Connect with likeminded individuals and discover the unseen world around you.
LaunchKit - Open Source - A popular suite of developer tools, now 100% open source.
Sayat - Sayat app is all about getting anonymous and honest feedback.
Profitable developer tools database - A database of 103+ hand-curated profitable developer tools
Sarahah - Sarahah is a Social Networking Application for providing anonymous feedback launched in 2016 and available to use on iOS and Android platforms.