American living in Germany. The thing you're not understanding is that "use roughly an ounce or so" will mean nothing to anyone in Europe. It's not about "recipes aren't important" but speaking the language of people who use your app. Locality is just as important.
I mean honestly though, if your problem is not being able to figure out unit conversions with a smartphone in your hand you might be putting the cart before the horse trying to learn how to cook well.
Learning to "eyeball things" is actually one of the most important skills I think you can have in the kitchen (not for baking of course), but when I see that I need 200g of an ingredient for a recipe, my first thought isn't "I can't believe the person writing this is from Europe!"
OTOH, it would literally take a few lines of code for the app to have conversions ready to go for you.
