Here are some of the personal/side projects that I build for fun:
This website - meaning adamcz.com - is the first project I built with Elixir and Phoenix. It's a simple self-hosted blogging platform, and an excuse to spend some time with amazing functional languages like Elixir and Elm.
Jazz Robot is a Ruby/Rails app that facilitates learning to play songs in all 12 musical keys. The site has been retired so that I could focus my attention (and hosting fees) on dbmaj7.com. I still love this app as one of my first attempts at building software for music education.