Great alternative to other note- or "PKM"-apps. Obsidian works with Markdown files in local storage, making it easy to use sync tools you already use.
What makes Obsidian truly great, is the plugin system which allows developers to create truly custom experiences. You can work with your Obsidian notes like in any other app, but using third party or even included plugins, you can make it your own personal second brain with back-linking, daily notes, a dashboard, tasks, and so much more.
This means that it requires a lot of up-front customisation to get it to look and work as well as other more "out of the box" apps. However, I personally feel like Obsidian, in comparison to these other apps, after configuration works a lot better with my personal workflow, as I can customise it in a way that works the best for me.
