I really liked Google Keep before I started concerning myself with privacy and boycotted all Google products. It struck the perfect balance between organization and the ability to easily jot things down; one thing I never liked about EN was that every note had to go in a notebook and had to have a title. That would always give me a mental block when I just wanted to write disorganized thoughts and then organize them later. I'm also a huge advocate of tags-over-categories.
Currently I'm on Apple's notes app. There are lots of things I don't like about it - rich text formatting needs to die - but it gets the job done and has "jot-ability". I've thought about writing my own dead-simple notes app but just never had the time. Plaintext, dropbox backup, simple substring search, maybe tags, maybe markdown.
That's super sketchy about the author.