Runkeeper, which started life with a running app and now wants to create a wider platform for health data, has raised US$10 million in a second round of funding.  The company wants to establish a network that will pull together a variety of user health and fitness data, broader than the kind of information available from standard running apps. Runkeeper first made an iPhone app that tracked runners using GPS and measured how far, how fast and how many calories they had burnt, followed by versions of the app based on Android, WP7 and Symbian. Then earlier this year the company decided the best way to match rival fitness apps was to become a wider platform. It introduced its Health Graph API in June and Runkeeper has now been integrated into more than 40 different apps or devices. Several hundred more apps and devices are also in the works for the future, according to the company.

The new investment for Runkeeper comes from Spark Capital as well as former AOL chief Steve Case’s Revolution Ventures. The two funds are augmenting additional funds from existing investor OATV. The new backing will be used to expand staff numbers from 14 to 40 before the end of next year and boost take-up of the Health Graph API.  Backing from its previous round was US$1.5 million.