This is my biggest pain point while working with heroku.
I own a SequelPro license (as well as licenses for a couple of other non-free tools, RazorSQL and Querious) and I always come back to DBVisualizer.
It's open source, so nothing's stopping anyone from adding support for other SQL servers.
(Disclaimer: I haven't been involved much with SP for almost a year now, so possibly there has been progress in that time)
Thanks for everyone's support.
I worked on and almost launched an open source bounty site a couple years ago. But the closer I got to launch the more I realized that I hadn't adequately solved all of the hard UX problems (mostly around a: picking who's going to work on it, trying to avoid both having two people separately do it due to know central coordination and having one person say "yeah, I'm going to do this!" and then not get around to it and hold the project back, and b: how to handle it when someone does technically address the bounty, but in a way that is unsatisfactory either because bounty-placers did not perfectly state their needs or because of poor quality.
Disclaimer: I actually like pgAdmin3, especially the visualized explain page.