I use instagram almost entirely to showcase my photography:https://www.instagram.com/imjustjk/. It's certainly not a perfect platform but it's good enough (and better than most). It's a mobile first platform that's simple, intuitive, and has huge adoption. It also has great loading speed for the amount of content and even the quality of images. I'm not sure what you expect on a mobile app? Do you want to be able to load full 42 megapixels images of mine on your phone?