List three things that you need to consider when designing an app.
Visual interface, user experience, performance and scalability, security, testing, and compatibility with different devices.
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
List three things that you need to consider when designing an app.

### Response:
Visual interface, user experience, performance and scalability, security, testing, and compatibility with different devices.