The Polarbear app has been a popular utility for posting to multiple social networks at once. They are revamping their app and have been in private beta for a bit. Now that they are nearing the final release they have opened up a public beta for you to sideload. The app currently lets you post to Facebook, LinkedIn, Tumblr, Facebook Pages, Blogger, Google+ Activities and App.net. In other words if you use more than one of them then it is worth the download.
Check out the update on the Polarbear website for sideloading. Kudos to DJ Reyes @CrackBerry for spotting it.