After open sourcing my first piece of software on GitHub (iOS-Screenshot-Automator) I decided to open source another component. It's called TSMessages and allows the developer to easily display little Notification/Messages on the top of the screen without stopping the user interaction. (similar to Tweetbot)
The notification moves from the top of the screen underneath the navigation bar and stays there for a few seconds, depending on the length of the displayed text. To dismiss a notification before the time runs out, the user can swipe it to the top or just tap it.
There are 4 different types already set up for you: Success, Error, Warning, Message (take a look at the screenshots)
With over 2.400 Favs on Github it's in the top 100 Objective C repositories on GitHub.