What Are the Best Party/Weekend Apps?

[torontowriter]

Preferably ones that are free.

I ran into this on reddit: http://weekendtrips.com/weekends-toronto/iphone-apps-for-the-weekend/
Can you think of anything better?

 

[r2shyyou]

According to their commercials, the Comm app seems to enable really fun times for all!

/sarcasm

Seriously though, I don't actually get what you're after. What do apps have to do with weekends & partying?