CamStudio Portable is a free, open-source software for screen and audio recording. It’s useful for people creating demonstrations or gamers trying to make gaming content. This design and photography software captures screen activity in either AVI or SWF. The software has its own SWF Producer that will allow you to do just that. You can also provide a visual aid to your videos through the use of subtitles or video annotation. Their website even contains an informative knowledge base you can refer to if you ever get lost. But seeing that its interface is straightforward and easy to use, that would be quite unlikely.