I've done a lot of research into this category on android, and there are a couple of good ones. For real drawing, Adobe Photoshop Touch https://play.google.co

I've done a lot of research into this category on android, and there are a couple of good ones. For real drawing, Adobe Photoshop Touch https://play.google.com/store/apps/details?id=air.com.adobe.pstouch https://play.google.com/store/apps/details?id=air.com.adobe.... Autodesk Sketchbook Pro https://play.google.com/store/apps/details?id=com.adsk.sketchbookhd https://play.google.com/store/apps/details?id=com.adsk.sketc... For simple and very responsive line drawing, Quill https://play.google.com/store/apps/details?id=com.write.Quill&feature=search_result#?t=W251bGwsMSwyLDEsImNvbS53cml0ZS5RdWlsbCJd https://play.google.com/store/apps/details?id=com.write.Quil... If your use case is more diagrammatic, try Skitch https://play.google.com/store/apps/details?id=com.evernote.skitch https://play.google.com/store/apps/details?id=com.evernote.s...