I do a fair amount of e-mailing in Japanese from GMail in Android. On my cell phone (Nexus One), I use Simeji to type Japanese characters, and it does a good job. However, I recently got a Samsung Galaxy Tab 10.1 tablet, and I've found the Simeji doesn't scale well to the large screen.
Samsung's Android keyboard, the stock Android keyboard, and Hacker's Keyboard are all installed on my tablet, and all of them have a nice, large, easy-to-type-on display on the 10" screen. Simeji on the other hand, although functional, is displayed with keys sized more appropriately to a 4" screen, and is stretched awkwardly around the bottom 10-15% of the screen. At least this is true in landscape mode.
I'd like to have a Japanese input method for my tablet that makes better use of the screen real estate, and is easy to type on with two hands. Does anyone know of one? Or alternatively, is there some way I can change Simeji's configuration so it works better on a 10" screen?
Update on August 20, 2011
As of August 2011, I've noticed that Simeji has been updated to work well on a tablet now, so it's no longer necessary to have an alternative. Still, this question may benefit future searchers who just don't like Simeji for whatever reason and want an alternative.