Good news for Microsoft (MSFT): Launching Windows Phone 8 seems to be helping the company create a real mobile app ecosystem. Todd Brix, the senior director of Microsoft’s Windows Phone Apps Team, announced on Twitter over the weekend that his company had seen a “100%+ increase in WP developer app revenues & downloads since WP8 launch in November.” Needless to say, this claim doesn’t mean too much without actual numbers to go with it since Windows Phone had such a low adoption rate before Microsoft’s grand Windows Phone 8 launch this fall. All the same, Microsoft must be happy that its efforts are leading to an increase in revenues for its developers, which could certainly lead to increased interest in developing for the platform.