APPlyzer - Professional rankings & keywords for app developers, marketers and publishers.
SmallDevTools - Handy developer tools with a delightful interface
Segment Sources - Load CRM, billing, and other cloud data to your Warehouse
LaunchKit - Open Source - A popular suite of developer tools, now 100% open source.
App Annie - App Annie is a marketing analytics tool available for apps of all kinds. With App Annie, you can track sales, traffic, and a variety of other factors pertinent to monitoring an app's trajectory.
Profitable developer tools database - A database of 103+ hand-curated profitable developer tools