SideWriter is described as 'If you often need to quickly jot something down, SideWriter is there with a flick of the wrist' and is an app in the Office & Productivity category. There are more than 50 alternatives to SideWriter for a variety of platforms, including Windows, Android, Mac, Online / Web-based and Linux. 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 apps like SideWriter are CherryTree (Free, Open Source), Zoho Notebook (Free Personal), Trilium Notes (Free, Open Source) and Tomboy (Free, Open Source).
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor.
Notezilla is the leading sticky notes app for Windows, Android, iPhone/iPad and the web. Set reminders to sticky notes, Pin sticky notes, attach them to websites, docs & folders, sync between PCs and other devices, organize using folders and tags.
The notes app for creative work. For the research, thinking and planning behind your next great piece of work. # Collect your thoughts Milanote is a place to put it all together. See your ideas, notes and research side by side.