Academic-Related
Comma DeliminatorThis tool converts characters within columns (e.g., Excel) and transforms it into a comma separated list (and vice-versa). I frequently use tool and find it's a great time saver.
Mendeley
Mendeley offers free software for organizing your PDF library. Some people prefer EndNote or Zotero, but Mendeley is my preferred tool for keeping a well-organized library of academic journal articles. I find that this makes conducting literature reviews a more sane process.
R Data Science Resource
This R resource is filled with a ton of great information for learning how to program in R. It's written by Hadley Wickham, who is the Chief Scientist for R Studio.
Rodeo
Rodeo is a stand-alone integrated development environment (IDE) for Python. I mostly code Python for back-end web development and find Rodeo extremely helpful for testing purposes.
Sublime Text
This text editor has great features for efficient coding and is generally aesthetically pleasing.
w3schools
This is a great reference for web coding/programming. This site was of great help while I learned html/css/JavaScript.
Hobby-Related
Guitar Play-along ToolThis tool plays songs (via YouTube) and displays the guitar chords as the song progresses. It's a fun and easy way to learn new songs on guitar. (You don't have to create an account or login--just use the search bar at top to find a song.)
Last.fm
Last.fm is a tool that records the music you listen to and saves it into a personal database. It's great for discovering new artists and reviewing past listening trends. If you're a quantative-minded music nerd, you'll probably enjoy this. I've been a user since 2005.
Playlist Converter
This tool allows you to transfer a playlist from one medium and hand it off to another medium. It works with (and between): Spotify, YouTube, SoundCloud, .m3u, and plain text. Pretty cool!