I want my application to be unsearchable from the App Store. I would like that only those users who sign in to my web site and then click the link of my iPhone application on app store, can install and use my application.
Is there any way to do that?
Not sure if this is going to work, but it may be worth a try:
You can set the release date of the application to the future. This removes the app from the catalog, which is a common way to remove an app temporarily (e.g. when it has problems) until an update appears.
However (this is possibly the catch) I don't know if the app will then be still available for sale via link or if the link will become unusable too.
if i were you i'd implement a "key generator", which will produce a serial that will be used to activate your application. this key generator would be free to access on your site, so whoever downloads your application through your site, would know what to do.
for those who access the application through itunes, i would also place a small text which basically says that you need to visit your site to generate a key. this way, you'd ensure that anyone who has access to your site has access to your app, and whoever finds your app will access your site.
this is i think hack proof by definition as well because noone would bother hacking it, would they? you basically give away your own serial generator for free, so it defeats the whole purpose of hacking. im assuming your concern is site traffic though.