Why not go one step further and produce something that can actually be used? My team uses our own frameworks to prototype in HTML/CSS, but when you don't have that I'd say the next best thing is Proto.io (http://proto.io). You can create interactive prototypes to test directly on the device in minutes without code.

If you really need video of interactions, I'm sure you can capture that from what you create with the tool. Even better, now you also have something tangible that you can hand to a potential investor or user to let them experience for themselves.

I'm not affiliated with Proto.io in any way. Since I prototype with code, I haven't actually used the product yet, but I've heard many great things about it. Hope this helps.