Thanks for quick review and test @makishart! Memory usage is being improved with each update, as you may have noticed app has quite a lot of feature that somewhat effect its performance. But step by step, improvements are released... About nsfw, due to AppStore/GooglePlay content ratings those images are overlaid with darker square in front page, but you should be able to see them when you open the post.
Thank you for your reply and your efforts on the app.. Yes I know that only the preview is black.. Maybe you should consider at some point to release a version without restrictions, available through download link or f-droid repository..
We do provide direct link through our github: https://github.com/esteemapp/esteem/releases
But they are same as other releases, in future I will surely consider this... Thanks!