Laura Fitton saw the upcoming apps gold rush coming back in 2009, when she launched the Cambridge-based, a niche app store for Twitter followers and application developers. Since then, she's raised some $2 million in Series A funding and has built a business platform for 20,000 developers to market their innovations, find advertisers and share ideas on a centralized community forum. By her own admission, this is an emerging, fragmented space but she believes it's promising for third-party application developers who want to bring their creative ideas to life in the mobile and social networking markets. "I saw a strong mandate to create a centralized website to make sense of all the tools because it was chaos before," says Fitton. "Twitter has open APIs, so you definitely can create anything you want. If you can create the software, you can integrate it with Twitter's APIs." There are a plethora of software platforms you can use to create such applications: Ruby on Rails, for example, or PHP. The software platform you use largely depends on the product you're creating the application for. For instance, TweetDeck runs on Adobe AIR. (For a list of platforms, check out the lower central box on the website.) is always on the hunt for third-party developers to sign up and promote their latest creations. But app stores also are searching for app developers to work in-house. employs three developers on staff. Though Fitton is a bit of a celebrity in Silicon Valley, she has no immediate plans to relocate from the Boston area. -- Sonia R. Lelii