The Fellowship of Game Parties for Android
Definitely lists GDC parties and provides information about the overall quality of said parties as submitted and updated by app users. Don't believe the current screenshots; the interface quality has improved quite a bit, but still needs a visual overhaul to increase its appearance of reliability and hip-ness. GDC should consider buying it from the developer and integrating it into their own current conference app.
by J####:
UI is awful, looks like it was developed 10 years ago. It appears that it's just a forum, in which case, should just use a regular website based forum instead so that you don't need the app.