I use Evernote to keep track of valuable information that I come across surfing the web or reading books. I'm still looking for a convenient way to automatically get my kindle highlights imported into notes.
I use Google Drive primarily as archive for printed documents that I scan using my iPhone.
I use Github as a source code repo, but also as a continuous integration and project management tool. Github has rapidly increased their innovation speed since they've been taken over by Microsoft, and now they replaced several other tools such as Trello or Gitlab for me.