PipeJump calls itself a "simple CRM for effective sales tracking." The service provides tiered pricing centered around "deals" that you are currently working on. You can send deals via email, embed a form on your site or set email reminders for followups. The PipeJump API provides read/write access to deals, clients, contacts and sources. Create your own interface to the PipeJump CRM.
There are currently no limits to the PipeJump API, though an account is required to use it. The service is RESTful, returning either XML or JSON.