Almost a year and a half ago I first mentioned the ShareKit library for enabling social sharing within iOS apps for urls, files, images, and text to many different social networks including Twitter, Facebook, and Tumblr (among others).
This library became extremely popular because with just a few lines of code you could implement social sharing with a very well made interface.
For some time there have been some issues with the library, but the official build was not updated, and updates have been very infrequent at the official repository. This meant you likely had to tweak it yourself or go searching for a working fork if you wanted to use it in a project.
This is now the ShareKit community repository and includes many updates from numerous forks, and the version has been updated to 2.0.
This build provides numerous fixes, includes support for more social networks (LinkedIn, FourSquare) uses native iOS Twitter support, and promises more frequent updates.
You can find the download repository here.
For up to date instructions you can check out the Wiki.
If you gave up on ShareKit because of the lack updates it looks like time to have another look.