MindNode

MindNode is a mindmapping application, it is a good tool for brainstorming and organizing your life—and iCloud & Dropbox support means you always have your mindmaps with you. MindNode lets you lay out your notes and tasks visually so you can get a bird's-eye view of your project. The interface lets you concentrate on generating and connecting ideas, and has an infinitely expanding canvas so you never run out of room.