I use IBISPaint.com, but take heed on it, there can be some questionable art. It is mostly kid-friendly though, and people draw cartoons, anime, and realism. However, to comment, like, download, you need a Twitter or FaceBook account, and to upload, you need one too. You also have to use the app to post, but you can vie the website for free.
https://ibispaint.com