The interface on Simplenote is elegant, minimalist, and easy to use. All you'll have to do is push a button to start taking notes. The only tools you'll need are a word counter and tags, so later on you can easily locate your notes without going through the hassle of looking for them.
In settings options, you can change font size, set up a security PIN for the app, or change the interface appearance (light, by default).
Simplenote is an app that takes great notes. It offers everything you need and nothing else, though an elegant, simple interface that will keep you organized.