Startup Idea: Nail Polish Color Preview App Idea

Startup idea to create a nail polish app that allows users to preview how various polish colors/brands will look on their hand by scanning their 'live' hand. The app should also have a history function and the ability to link with specific salons' color/brand inventory.

I am a nail technician. Often people have trouble choosing their nail polish color because although the colors stay true to what they look like in the bottle, these colors can either complement the skin tones of the client, or they can clash. That is why I was so excited to download this app:

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Problem is, this does not work very well! It's supposed to show different colors of polish on the "live" nail tips. But you cannot model your hand and control the app at the same time! Seems like no one thought about this. Anyway, this particular app only is good for that brand's polish. I want an app that will scan my client's "live" hand, scan or refer to the color/brand and show how it will appear on her hand (but don't show that part live). My clients would certainly enjoy this and I would be happy to pay for it. They could even download it to their own phone and pick out/try on their polish before they come into the shop (app should have integration with my particular salon with the colors/brands I carry in stock).

Also it should have a history function. I think a lot of women would love this.

Thanks!.