Courtmatics Smart Tennis Coaching System - Instant coaching & detailed feedback on your tennis game
Steam Inventory Helper - Steam Inventory Helper is a free browser extension for Google Chrome that adds a big amount of new features into the Steam trade-offer system & Steam store functionality.
Smash Tennis - Makes finding tennis partners easy
Augmented Steam - Enhanced Steam fork by IsThereAnyDeal.
ShotTracker - Boosts basketball players' shot by measuring performance
Steam Tools Hub - A set of Steam related WebApps built around trading cards, emoticons and backgrounds.