I'm a programmer in the finance industry working on low-latency trading systems.<p>Over the past few months, I've become interested in web development and have done a few internal projects at work.<p>Now I'd like to create something public to demo my skills. My goal is to create a slick single-page web app, to be open-sourced on Github.<p>The ideas I've come up with so far are:<p>(1) Blackjack trainer: teaches the user how to play blackjack methodically. There are quite a few sites that already offer this, but the UX is mostly crap reminiscent of the late 90s.<p>(2) A Glassdoor for apartment rentals: a site where you can comment and rate your apartment building, share how much you pay, photos, etc. Generating content for this would be tough.<p>(3) Retype the masters: where you re-type the works of the great writers; Hemingway, Fitzgerald, Gatsby, et al. This idea was lifted from this page: http://grahamwahlberg.com/business-ideas/ (last item). I personally like this idea the most but a quick check shows that a lot of the works by these authors are not in the public domain.<p>4) Create tools or components for Reactjs: I love ReactJs so perhaps some open-source contribution would be good here. I just don't know what.<p>5) Create a framework for stockfighter.io: stockfighter.io is a stock market programming game. While it has a UI where you can enter trades manually, the only real way to get anywhere is to write programs to trade the scenarios. My framework would provide the things stockfigher doesn't provide such as a container for your trading strategies, a module to update your strategies on market movement, a position blotter, etc. This wouldn't really be a webapp though.<p>Do any of these ideas appeal to you? Is there something else you would suggest?