(keitai-l) successful i-appli?

My dear keitai list,

I tried to ask this a while ago, and was surprised by the lack of response
(possibly due to my inability to phrase the question clearly :).

What are examples of successful i-appli (not i-mode)?  By successful I mean
either "developers made impressive profits" or "users love it."

I"m not looking for detailed research; just wondering what you use yourself,
and whatever apps you seem to hear about a lot.

thanks,
-Josh