Consider how many iPhone apps work essentially perfectly on the iPad, though — it's an awful cliche, but imagine if you're the maker of a 'fart app': do you do

Consider how many iPhone apps work essentially perfectly on the iPad, though — it's an awful cliche, but imagine if you're the maker of a 'fart app': do you do that much better by scaling your UI [still just supporting the exact same set of features... it's not like an iPad runs such apps better than an iPhone does] to fit the iPad a tiny bit better, or by adding more and better fart noises to your existing iPhone app?