When is an application considered complete?

Scrum asks you to define the DONE! They call it DoD (Definition of Done) when you are going to begin be development process. DoD has its own specifications, it should be clear and achievable.

Having a DoD you can clearly know when the software development process is Done.

When it FULLY goes through the stages of Software Developement Life Cycle (SDLC) which includes:

1. Requirments Analysis (Gathring project requirments and analysis. i.e what really customer needs and what he/she don't need).
2. Design (Initial design and prototyping for the application).
3. Implementation (Implementing the design and writing code phase).
4. Testing and Documentation (Discovering bugs, insuring that it's fulfilling customer needs, etc..)
5. Deployment and maintenance, Evolution (Depolying application to the production environment and adding other features if customer demands then the whole phases loops again).