New services are being added to Singly all the time. We have a very rapid release cycle, with Facebook likes, Yammer, and Runkeeper all being added in the past week.
We're absolutely open to adding any service that the community wants. Throw up your suggestions on our uservoice page at
http://singly.uservoice.com. It also serves as a rough list for what services we will add in the near future.
You could also post the request for managing the Facebook page tokens, and our engineering team will discuss the feasibility of providing that feature in the near future. Providing easy and widely-supported auth is definitely one of the great use cases for Singly.
Pinterest, however, is not likely coming as there is no public API for us to access. They have made noises about releasing one, and we're certainly keeping our eye on it.
--Justin