Writing Streak is described as 'A simple but powerful tool that helps writers to develop a daily writing habit, increase productivity, measure progress, achieve writing goals, and master the art of writing in a fun and engaging way' and is an website in the News & Books category. There are more than 100 alternatives to Writing Streak, not only websites but also apps for a variety of platforms, including Windows, Mac, Android and Linux. The best alternative is Joplin, which is both free and Open Source. Other great sites and apps similar to Writing Streak are Standard Notes (Freemium, Open Source), Notion (Freemium), Typora (Free) and Evernote (Freemium).
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.
With so many tools, it's hard to keep everyone on the same page. Notion is a new tool that unifies them all. It's like Google Docs, but everything is organized and discoverable by your team. Real collaboration in real-time.
Manuskript is an open-source tool for writers, with outliner, character management, plot development, distraction-free editor, etc. Outliner Organize your thoughts and snippets in a hierarchical manner. Organize them as you wish, reorganize them on the go.