HealthVault is an open platform where developers and partners can build their own applications that leverage the HealthVault architecture. While Microsoft provides tools to developers who would like to build HealthVault-enabled applications (via the MSDN), partners are responsible for application development. The following links are to the MSDN and are relevant for technical personnel.
If you do not have the technical expertise or capacity to build your own HealthVault-enabled application there are HealthVault consultants that have experience creating HealthVault-enabled applications for clients. These consultants can be found on the consultant directory on MSDN.