How to determine that user runs the app for the first time?

Question

I got a problem of my iOS app recently. In my app, an instruction view will appear at the first time of running, then hide from then on. How can I implement this effect?

Answer 1

The only way I think is to store a value into a specified file, when run the app, you should check the value first, and then you can deal with the result whether the app has already been run.