How will you invoke other apps from the native iPhone app?

How can I invoke an app from a native app? I want to invoke my app on clicking a mail from the native mail app. For example native mail app list staza app and 开发者_如何学运维good writer app when you want to view a pdf file, that is in your inbox.

So what we should do if we want to display our app also in that list?

You can try inter-process communication. Here is some guide