My 'simple' answer would be to do record a screencast of your software. There are many advantages to that.

1. No trouble with live screencast, network...
2. You can add some effect (zoom in,..) to focus on specific functionalities
3. You are in control of your time and don't loose your prospect/investor time

I use Screenflow to do my screencast on iOS or OSX. Super user friendly imo.

I hope this helps a bit.

If your prospect/investor wants to see more, this is a good sign, and then you can show more on a 1-to-1 meeting or suggest to install a test version of the app so that they can get their hands on.