pixiv Sketch is a new communication platform that allows you to enjoy your daily sketching more easily than ever before. Centered around sketching anywhere and anytime, pixiv Sketch supports PCs, smartphones, and tablets allowing you to enjoy communicating with others. You can use pixiv Sketch right away through your pixiv account. It’s free to use.
Online version: https://sketch.pixiv.net/
iOS App:https://itunes.apple.com/us/app/pixivsketch/id991334925
Android App:https://play.google.com/store/apps/details?id=jp.pxv.android.sketch