edit: I have updated list of known projects. Thanks for suggestions.
OKOin - Platform and headset for VR porn - ICO
vicetoken - Platform for watching and sharing porn. ICO soon
sexcoin - dead
boobscoin - dead
bigboobscoin - dead
Livestars - Webcam service meets cryptocurrency. ICO ends on 14.2.2018.
Spankchain - Platform for webcams atm. More projects in future - Active development. Also runs cryptotitties.
wankcoin - dead
titcoin - looks dead
kencoin - Website doesnt load, 137 followers on twitter = dead?
Porncoin - Payment method and use of the face recognition for porn industry. Post ICO
sexService - Sex dating service based on a blockchain.
As it is not banal sounded, but pornography has always interested people. So choose from those projects that you yourself would use )))) And very carefully look at the fact that the team already had some ready developments that are already used by people. In my opinion it will be the most correct approach.