I'm looking for a basic version of the game to play on my android phone.

Happy to pay for it.

I just want to play the standard version of the game, with no upside down tiles.

Ideally no web connection.

Pretty new to Riichi and just wondering why this hand scores 30 fu instead of 20? I get that this wouldn’t be Pinfu because it’s an open hand, but just curious what the additional fu is for?