Generally, building an app would take around three to nine months. That may vary depending upon the complexity of the app and the structure of one's project. Every stage involves a different amount of time to complete. To gain perfection at every step needs devotion of time.
Various stages of app development are as under:
1. Planning and constructing a project brief.
2. Researching your ideas with the developers.
3. Design sprints: six to twelve weeks.
4. Development and prototyping.
5. Deploying to the app store.
6. Continuous improvement.
7. Post-launch support.