PileMd

PileMD is a cross-platform piece of software that aims to offer you the best parts of three different types of utilities, namely, a Markdown editor, a text editor and Note Manager.

User-friendly app that does not require installation

Since it does not need any third party utilities to run, you can get started with this program right away by unzipping the package and by running it via its executable file.
Upon first launching it, you are met by a well-organized main window and a "welcome note" that displays a list of all the app's essential features. Its interface looks modern enough to feel right at home on the latest iterations of Windows and the basic layout is pretty straightforward.
On the left side, you can get a quick view of your notes and quickly organize them into folder via drag and drop gestures, while on the right side, you can format the text.

Automatically saves your work and comes with a live preview Markdown editor

Before anything, it needs to be taken into account that the app supports basic Markdown editing. Even more so, it also comes equipped with a live-preview, interactive text editor, which means that you can instantly see how the text will look in HTML form.
The app automatically saves all your work in a local folder of your choosing. Additionally, it can undo or redo a few of your latest moves, open links directly in your default web browser, import Markdown files, as well as arrange notes by their creation date or by the date they have been modified.

Interesting for some, frustrating for others

While, at least in theory, having an app that can act as a Markdown editor, word processor, and note manager is not a bad idea, in this case,  it means that the app is not very well equipped to be granted either title.
As a Markdown editor is lacks more advanced features like support for extensions, typical options for exporting your work directly to HTML or PDF and other syntax helpers.
As a word processor, it does not bundle features like spell checker, advanced text alignment capabilities (justification, centering, decimal alignment), page numbering and support for footnotes and, as a note manager, it simply does not provide you with the possibility to quickly organize them, nor does it provide support for other types of notes such as checklists, voice memos, etc.

A versatile and accessible application

All in all, PileMD is not a bad piece of software at all, actually, far from it. It manages to blend basic features found in multiple utilities, while remaining relatively user-friendly.
Probably the best way to look at PileMD is to view it as a basic, not too extensive, Markdown editor that also packs a small set of features form the other previously mentioned two.