Sortd - Rated the #1 App for Gmail
Developerhub.io - All-in-One Platform for Online Documentation
KanbanMail - A Kanban board for your emails.
PortaCrypt - Create portable encrypted documents on your Mac
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
ReadMe - A collaborative developer hub for your API or code.