Pornhub have Android app for download outside of the stores (there are few other similar Android apps too), but it is not possible for Apple apps.
It is not worth the risk as they will strike your business account permanently, and you will not be able to register again unless you have a different business and you are a different person with a different id.
Instagram, Facebook, Twitter and all the big companies can somehow get away with few adult account if not one complain, but even Snapchat starting to close adult accounts.....
Onlyfans and snapchat are the only sexting/adult apps today, but does it worth the investment? The girls know to ask PayPal payments for Skype or texting... they can always use regular messaging apps "privately" and no one will say anything because it is "private"..
If you want ideas for apps see
https://www.spankchain.com
They plan to reinvent the adult industry (cams, clips4sale, free tube site) using their own currency..