I have applied to NSF's Software Infrastructure for Sustained Innovation program for a developer for TreeTapper and some salary support for me. Consistent with TreeTapper's open way of doing science, you can see the submitted proposal (minus the legalese pages and my CV/other grants pages) here (PDF). The goals are threefold: 1) improve the basic TreeTapper code to make it more sustainable, secure, and faster, 2) improve usability, esp. with generation of the missing methods/software diagrams and with user login (implement OpenID), hopefully making it easier for others to get involved, and 3) make the code base deployable in other fields -- imagine a TreeTapper for methods in astronomy or ecology.
Continued thanks to NESCent for funding initial development of TreeTapper (feeding me, hosting the site, providing extensive expertise) [NSF grant EF-0423641] and Google Summer of Code for funding a student to create code for visual database traversal.