There are lots of apps designed to help you make more of your handset's movie and image capturing capabilities, but MovieJax for Windows Phone stands out for a couple of reasons. It is really, really easy to use and it works on those lower cost Windows Phone handsets that don't have a lot of RAM (it only needs 512MB).
You can capture video from within the app itself, and join different videos together to make a longer sequence. Videos are easily cut to trim them to size. Incorporating photos is no problem either, and you can add music and text – you could, for example, create a credits section.
MovieJax is a Windows Phone only app at the moment, and it's a freebie. Go on; download it in preparation for the summer hols.
OS: Windows Phone