The latest version of Evernote for iPhone and iPad adds your finished sketches to notes and puts your handwriting through its optical character recognition (OCR) system, to make the text searchable — assuming your writing is legible, of course. Scribblings sync across platforms and devices, including Android, Mac and Windows, where they can be edited or deleted. And you can choose from various drawing widths and colors.
Evernote's sketching and handwriting features worked as promised in my tests, when I used my right index finger and the Adonit Jot Dash ($50) for input. If you use Evernote on an iPhone 6s or 6s Plus, the 3D Touch feature also thickens or lightens the line weight of your drawings as you adjust the pressure.
Unfortunately, Evernote didn't go far enough with the new features. You can't zoom in or out while sketching, for example, which is limiting. More importantly, while you can add hand-drawn images and text to notes, it's difficult to insert them exactly where you want them, or remove them if you insert them in the wrong place.
In other words, annotating notes with a stylus or finger still isn't an Evernote strong suit. I'd like to draw circles around important paragraphs in articles saved to Evernote, but I can't. Evernote's drawing tools let you freely annotate images within notes, but that's where it draws the line, pardon the pun. A cross-platform, standardized stylus input for Evernote notes, as well as images, would be a very welcome addition. (Evernote's Skitch app provides some of this functionality, but it's a separate download with a focus on annotating images and PDFs.)
If you seek the most fluid stylus or finger input within notes, the killer combo of a Microsoft Surface tablet, Microsoft stylus, and OneNote is the best option I've found.