Classy

Launched 06/09/2014

Classy is a linear algebra based recommendation engine for classes  that UW students should take. It works by creating a vector space out of  all of the recommendations it has so far seen, and then using a  technique called the SVD to reduce the vector space and find  similarities between recommendations.

Links: Paper (PDF)


Backito

HackMIT 2014

A decentralized Kickstarter clone. This was at a hackathon in 2014 before Ethereum had shipped. Solidity didn't exist yet and everything was set up manually. The project won 2 BTC in prizes from Coinbase and General Assembly.


Bottle

Launched 01/19/2014

Bottle is a new way to experience places you go. Each picture you take sticks to the location where you took it and is only visible to those nearby.

Update (2019): Bottle was taken down a couple years ago, but it was the same thing as Snap Map, just 3.5 early :)

Links: Website App Store


FaceOff

Launched 02/12/2013

Judge your friends (anonymously) on Facebook! As if you already don't.

Links: Facebook App


UpYours

Launched 09/25/2012

UpYours is an image-based leaderboard for all trendy topics. Who's the best football player in the AFL? Answer on UpYours.

Links: Facebook App


Arithmetic Calculator

Written in 2008

A command line calculator that evaluates arithmetic expressions and functions. Features include factorials, powers, brackets, bracket normalization, polish notation, factorization, user defined fields, equation solving, and advanced error reporting.

Written to learn language grammer/parsing and to help me do my math homework quickly.

Links: GitHub