I use it for several projects and it is worth buying it. I can time my tweets to Facebook and Twitter. I can set the repetitions and post as a "company accounts".
The developers are cool, because they listen to improvements and I have seen them realizing several of my suggestions (far sooner that I had expected that). It can be cleverly configured, for example to use the API of YOUR bit.ly account, so you can track the success of your shortened URL. A very clever and useful extension. So my thumb is up