Drunk per dollar.

I've always maintained that if I ran a liquor store I would add a section on my price labels that displayed the "drunk per dollar" of each beverage. It would just be PeV/Pr, where Pe is the percentage of alcohol, V is the volume of the container (in ml), and Pr is the price. Simple. Milliliters of alcohol per dollar.

But here's the thing, why doesn't someone make an app that does that? I mean, I know it's an easy calculation, but if you made a pretty-looking program with three little clearly labeled input boxes (you should be able to input the volume in metric or imperial and have it convert) and one button. Poof. Sell it for a dollar a copy. Send me 20%.

Also, since we're making a app for phones, make an augmented reality feature ("liquor goggles") where it looks for barcodes, reads them on the fly, uses the internet to find out the proof and size of the product from that, grabs the largest nearby number, assumes that's the price in dollars, and floats a DPD number right next to that. If phones have the megapixels and speed to keep up with a bunch at once, have it change the colors of the DPDs to easily rank all the numbers presented on the screen at a time. Boom. There's a product.