Definitely needed. An extremely explicit image for a community I don't subscribe to was immediately visible on my screen on first launch of the app. In public sitting in a park. Luckily no one around me.

Blurring NSFW is needed as an app setting (and it should be on by default) so the user can contextually see or not see it, but never have this kind of content surprise show on their screen.

In addition it would be good to be able to prevent nsfw content from showing up on the main feed in general. Even if blurred, it could be embarrassing out in public for someone to see the blurred image or title — or just not something the user wants to see themselves on their feed.

NSFW communities should be kept out of algorithmic recommended feeds in general probably as a default unless the user subscribes to them — but even then a setting to show or hide the community from main feeds could be very useful. I'm not sure how much control you'd have over this on the app side or how much of this is determined by Lemmy on the server, but these kinds of user preferences for how to view feeds and communities and different kinds of posts hopefully become more powerful as Lemmy and Lemmy apps develop.

It's looking like a great start to the app! I'll have to hold off using it again at least in public haha until NSFW blur is in place, but looking forward to watching the development!