Black Blocks - Validate first.
HMTMAA - Clever tool to estimate cost of building an app
Lean Canvas - Business plans take too long to write, are seldom updated, and almost never read by others but documenting your hypotheses is key. Lean Canvas solves this problem using a 1-page business model.
Omni Calculator - Helping you make rational decisions, one calculation at a time.
Idea Validator - A customer development tool to help you validate your ideas before building them.
Cost of Living Calculator - City comparison tool to see how far your salary will go