Well, that's the name of the app, that's how it's found in the Play store.
It means: Japan Sumou Union public app "Oozumou".
It's free, but you can't install it outside Japan, it just provides an interface to the Union's website at http://sumo.or.jp/
which is otherwise very inconvenient to navigate on the phone.
If anyone could install it and provide it, I'd be much obliged.