4Media Video Editor lets you join, split and cut your videos. Each of these functions open a new app. They all look similar and are very easy to use. The same video formats are supported across all three apps, and some of those are: AVI, MPEG, WMV, MP4, FLV, MKV, H.264/MPEG-4, DivX, XviD, MOV, RMVB, ASF, and 3GP.
The first app lets you join videos together. You do this by dragging and dropping the videos that you want to merge. You can drag as many videos as you want and you can even add a fade in and fade out effect so the transition between videos is smoother.
The video splitter lets you "split" a video file in two or more parts. There are a few of different ways in which you can do this. You can either select the split point manually, or use one of the automatic split modes. These let you split your video every X number of minutes, every X number of MBs or to split the video in any number of parts.
Finally, the video cutter lets you trim your video. You simply select a start point and end point and that segment is saved and the rest is discarded.
All the features worked well in my testing. I am not crazy about the $50 price tag, but the app does work well.