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.
Skuuudle - Discover, match and monitor your eCommerce competitors.
AppFollow - AppFollow is an integrated solution that makes monitoring, analyzing, and elevating your app's reputation easy.
Price2Spy - Price2Spy is a price monitoring, pricing analytics, and repricing tool, meant to help eCommerce professionals keep an eye on their competitors or retailers.
Sensor Tower - Sensor Tower is a platform for app store optimization and app industry intelligence.
BuiltWith - Find out the technology behind websites