1. Define the Problem and App Solution
2. Define Personas
3. Find the Use Case and User Story
4. Find the feature list
5. Prioritize the feature list (user story? scrum? kaban?)
6. MVP
7. Define main work flows and others.
8. Prototype High Level Wireframe
9. Confirm the wireframe and prototype with users
10. Coding and Testing
references:
https://www.udacity.com/course/ux-design-for-mobile-developers--ud849