A special link that’s clickable on any iOS devices such as iPod, iPhone, or iPad and go straight to Apple’s Appstore can be built via iTunes Link Maker (Create links for the iTunes Store, the App Store, the iBookstore, and the Mac App Store).
The only thing we need to do is to search the app on the search box and click on the *device* App Link on the very right column of the table.
As an example, if we want to create a weblink for “Plants vs. Zombies,” we just need to type in the title in the search box.
As the search results are displayed, select the intended app whose link we want to create.
After clicking the link, just copy and paste the whole markup in the HTML With Link: dialog box. You can choose among three options on how the link will be displayed (Small button, Large button, or Text Only).
The beauty of this, if it’s clicked from a non-Apple device, it will open an iTunes Preview page of the application.
Here’s the final link pasted on this very page in all three versions:
Plants vs. Zombies HD – PopCap