This is a great tool for presentations. Flowgram is like a screen capture, where you dictate and record what is on the screen. But it is better, because all the web pages are live, and you can use them just like the regular web. This is great to show students an exact part of a web site, and an exact part of a web site, and talk about it.
Or better, have them show you something that they found, and tell about it in English. Try the sample here.