Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Tyke - Mac menu bar app that @torrez really needed to take notes
Qiqqa - Qiqqa is a free research and reference management software. It can be used in many organizational projects from the academic to the personal to the business endeavor. Read more about Qiqqa.
Thought Train - Stop using sticky notes to remember what you're doing 📒 🚫
JabRef - Graphical Java application for managing bibtex (. bib) databases.JabRef · JabRef Help · JabRef | Blog · OpenOffice/LibreOffice .