It's not more so who gets offended by the view of a bare butt, but it's more Google and Apple that requires these apps to adhere to their policies and standards. As an app owner you need to balance making sure you comply with their policies if you plan on having an app on their store, but also making sure you keep your customers happy.
I think Toomic does a very good job of keeping both happy. They have an app that strictly follows Google and Apple's guidelines, and then if you want to read and see mature content, you can do so on the website.
Honestly, with the way the world is going and more and more people using their phones/tablets to surf the net, I would build and focus my priority on a website that is mobile compatible rather than an app. This way you don't have to cater to the big sharks and focus more on your customers and their wants and needs @ratique