As far as I understand, your idea is to have an app to interact with the waiting staff without having to call a waiter. What I'm thinking:
Better website - there are lots of good product landing pages and templates out there to emulate. Right now it looks like something for a not-so-popular open source software package, such as http://izpack.org/ or http://www.tryton.org/
The introduction video is FUBAR right now. It is too long, contains too much cruft (how-to-use should be left for another video), the font for text doesn't fit the purpose, the text should actually be replaced with narration. I think the gold goal in this space is something like Square or Erply have done for their videos. Basically, just try to show the main use case anyone should use your app for.
About the idea itself - have you done any market research, are there business owners who would be willing to use it?