There is no way you can tell if a user added your app to their profile. I'm not sure what iLike is doing on the backend, but it seems they prompt to post to your profile on install. By default, the profile has nothing, you need to post something to it.
Normally this is done by displaying a special button that Facebook displays if they don't have the application already in the profile. But Facebook also won't display the special button if the profile has no content. So it's a chicken and the egg scenario, which comes first?
You can query what is currently in the users profile (getProfileFBML), so you could possibly use this as a check to see if they have added your app to the profile. If it's empty, you never posted any content their. But you can't tell if they subsequently removed it, or moved it to the Boxes tab (which is useless).