Team Obama is once again rallying the masses on social media, with the first-ever inauguration smartphone app. The inauguration's official Twitter feed, @ObamaInaugural, has a meager 38,000 followers compared with @BarackObama's 26 million, but it's more than three times the size of the next-biggest inaugural feed, @inaugurationWDC, with more than 11,000. Volunteers can earn a Foursquare badge by checking in at any National Day of Service event, and revelers can get pumped up by the celebration's official 17-song playlist on Spotify. The inauguration Facebook page has the largest presence so far, with 271,000 mentions and 49,000 likes. That's just over half the "likes" received by Aretha Franklin's meme-tastic inauguration bow hat, which stole the show in 2009.