Idea
Articulate that idea -- conversation, written, etc.
Distill that into a 'spec' (written)
Brainstorming
[FINAL PROJECT STAGE]
Refine spec into a detailed project description including timetable -- intermediate deadlines -- and visuals.
Prototype/comp one 'leg', one avenue, one whatever of the project.
Plan on rolling out an alpha version (working version)
Test, test, test -- the technology, the concept, the usability.
Get to a Beta version (almost ready for primetime)
Test, test, test.
Launch coordinated with marketing/PR/social media strategy.
Respond to any queries.
Fix/tweak/refine.