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.
Better Notes - Simple notes app that ties notes together with #hashtags
Create Issue Branch - Automates the creation of issue branches on GitHub
Startup Notes - Most actionable advice from each Startup School speaker
REVISR - Git Management for WordPress : keep track w/ version control
Thought Train - Stop using sticky notes to remember what you're doing 📒 🚫