During an excursion to McDonald's with a few of my friends, we decided to get a bunch of stuff off the dollar menu, but couldn't decide on what to get. This nifty web page takes out the hassle of doing exactly that by flipping a lot of coins to figure out what you should buy.
How it works
Given a restaurant, a budget, and a couple of other settings (like vegetarianism), the Mystery Box will query an array of objects containing dollar menu items from that restaurant at random, repeatedly, until the sum of prices adds up to the budget given.
Everything is kept on the client-side, so there's no need to deploy this to a server. You can just download it from the repo and open up index.htm in your browser, or check out the link hosted on my website.