SideNotes is described as 'Clean and handy notes on your monitor side' and is an app in the Office & Productivity category. There are more than 100 alternatives to SideNotes for a variety of platforms, including Windows, Mac, Android, iPhone and Online / Web-based. The best alternative is Joplin, which is both free and Open Source. Other great apps like SideNotes are Standard Notes (Freemium, Open Source), Notion (Freemium), Google Keep (Free) and Microsoft OneNote (Freemium).
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.
Nirvana is a secure, cloud-based GTD® task manager accessible from your desktop web browser and mobile devices. If you have more to do than you can manage in your head, or if you want greater clarity of mind and focus in life, Nirvana is for you.
Notational Velocity is a mouseless application for storing and retrieving notes. With Notational Velocity, searching for notes is not a separate action; rather, it is the primary interface. Searching encompasses all notes content and occurs instantly with each key pressed.
Foam is a personal knowledge management and sharing system inspired by Roam Research, built on Visual Studio Code and GitHub. You can use Foam for organising your research, keeping re-discoverable notes, writing long-form content and, optionally, publishing it to the web.
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.
ColorNote is a simple notepad app. It give you a quick and simple notepad editing experience when you write notes, email, message, shopping lists and todo lists. ColorNote makes taking a note easier than any other notepad apps.