I have created an application using iframe / Javascript. I developed the whole application , I tested with my and one of my friend's FB user Id. It worked fine.
Now when I try from a third person's Login but I could not find my application from serach box.
I have already turned off "Sand Box" mode. So that it is available to general users.
Right now it is only availble to me and my test user.
What happens when you access the app directly through it's namespace?
i.e http://apps.facebook.com/{appName}
Just because the result isn't returned by search doesn't necessarily mean the app isn't working.