And runs on Mac — probably anything that can use Java (so, not an iPhone/iPad). Keyboard shortcuts are different but otherwise, it works exactly the same.
God forbid they give us an official dark mode though! There is a hack, it doesn't survive reboots/updates though and the thing updates a few times a day... I stopped trying after doing it a few times.
But yes, Jd2. Usually you can throw a link at it and it will parse it and give you the file. Though on sites like OP asked for, they are almost always lo-res and watermarked.