Ok, so I want to join / merge some avi video files. What's the best app for doing so? I've had a look on the app store, and none of the apps seem to get decent reviews. Only the Xilisoft Video Joiner app has anywhere near an ok review, but even then, the negative is that the app only uses a single core, hence is very slow at converting. Preferably, I'd like a free app, but would pay if there is anything that will merge files quickly, and keep them at a decent output size. As an addition, are there any decent apps for converting videos to xvid format, which keeps file size to a minimum?