How to check if an app is installed from a web-page on an iPhone?

Question

I want to create a web-page, a page that will redirect an iPhone to the app-store if the iPhone does not have the application installed, but if the iPhone has the app instal

Answer 1

Didn't read all of these but may be use an iframe and adding the source to, "my app://whatever".

Then check regularly on set interval of the page is 404or not.

You could also use Ajax call. If 404 response then app is not installed.