Wedgies - Realtime polling over social media
SmallDevTools - Handy developer tools with a delightful interface
Poltio - Create and share questions, get answers.
LaunchKit - Open Source - A popular suite of developer tools, now 100% open source.
SurveyMonkey Intelligence - Usage and download metrics for all mobile apps
Profitable developer tools database - A database of 103+ hand-curated profitable developer tools