Cherkalka!

Three in one: the app to create notes, photo editor to alter images in Photos, action extension to make changes on the fly. Cherkalka is a great tool when in need to note quickly on a photo, just to sketch or write, all these without launching a heavy notepad. The full version in addition can: resize the note; move and rotate layers of strokes and background; scale the current note view; change width and color of a pencil in the photo editor and the extension; sync notes via iCloud; to not show the app logo on exported pictures.