Notestack.me is described as 'web-based Simplenote client for the modern browser. It takes advantage of browser localStorage, a new HTML5 feature, to store your notes locally and make them available even when your internet connection is down'. There are more than 50 alternatives to Notestack.me, not only websites but also apps for a variety of platforms, including Windows, Android, Mac and iPhone. The best alternative is Joplin. It's not free, so if you're looking for a free alternative, you could try Standard Notes or Evernote. Other great sites and apps similar to Notestack.me are Simplenote (Free, Open Source), CherryTree (Free, Open Source), Zoho Notebook (Free Personal) and Trilium Notes (Free, Open Source).
WizNote is a Note software, which is especially designed for Internet users and mobile Internet users. WizNote focuses more on notes of rapid collection, management, reading and sharing. WizNote is smaller, more stable, and more suitable for computers, phones and mobile devices.
NixNote, formerly Nevernote, is an open source client for Evernote . It is written in Java so it will also run on Windows & OS-X, but the primary focus has been to try and get a usable environment for Linux.