The app, step by step. The rules are on their own page; this is what you'll see and what to tap.
Someone deals a game and picks Oh Hell at the top of New game. You get the invitation the same way as any table — say Deal me in. The table deals itself when everyone has answered.
Across the top: every seat, their bid and the tricks they've taken this hand, and their total. The line under it says which hand this is, how many cards, and what's trump. Scores opens the whole game so far.
When it's your bid, pills 0 to N appear under your hand. Tap one, then Bid. If you're the dealer this hand you bid last, and the number that would make the bids add up is crossed out — that's the hook.
The trick sits in the middle with a name under each card; the trump card stands beside it. Tap a card in your hand, then Play. If a suit was led and you hold it, the rest of your hand sits dim — you have to follow. Take the trick and you lead the next.
When the last trick is taken the feed says what everyone scored — 10 plus tricks if you made your bid, 0 if you missed — and the next hand is dealt straight away.
After the last hand the results card comes up: the order, the scores, and the hat on whoever came last. Rematch deals the same table again.