> Making sure you're not showing them by nsfw content, etc. or your advertisers will pull out.

Which you can control by just returning the ads as part of the API response for the feed, which I'm sure how the official client does it. Making the client classify NSFW content and hide ads based on that seems like a stupid idea.

Certainly, but the second you get a rouge actor, your advertiser is going to be pissed.

At the very best the rouge app won't display ads.

At the worse, they'll ignore a nsfw tag and won't show the spoiler overlay, angering your advertiser.

Audits can catch it, but only after the damage is done.

I don't think there's any service that lets their ad supported plan be in the hands of a 3rd party client.

Enforce it on clients over a certain number of users where they are big enough to manage following a bunch of rules around the ads. Then they can be audited to make sure they get doing it correctly.

Yeah it can be done with X amount of risk and auditing ($)...

I was mainly asking has it been done by any service?

Risking your advertisers is not wise and audits will be expensive and reactive not proactive.