WaniKani Daily Digest (https://wanikanidailydigest.com/): WaniKani Daily Digest collects relevant information for WaniKani users every day and compiles an email with additional statistics about how they did compared to the previous day. It was built using Ruby on Rails.
WaniKani to Anki Exporter (https://wanikanitoanki.com/): WaniKani to Anki Exporter was built to grab information from WaniKani via their API and generate files that can be imported into Anki. It was built using the Padrino framework, and the code is currently open sourced.
wanikani (https://github.com/dennmart/wanikani-gem): This is a RubyGem that uses WaniKani's API so you can hook it into any Ruby project.
wkcheck (https://github.com/dennmart/wkcheck): This RubyGem is a command-line tool to easily access information from a WaniKani account.
Previous startups I've worked for
Storenvy (http://www.storenvy.com/): Storenvy is an e-commerce platform that allows anyone to open their own online store quickly and easily, and for free. It also contains a marketplace for discovering amazing products from emerging brands. I was part of the engineering team responsible for the Rails backend.
BarterQuest (http://www.barterquest.com/): BarterQuest is an online trading platform where individuals and businesses can trade goods, services or real estate. I was brought in pre-launch and helped build most of the features on the website as they exist today.