Obsidian is definitely a great tool for knowledge management, and now it's even able to do all that on mobile!
Personally, I've used our tool Hypernotes (https://zenkit.com/en/hypernotes/). It released with a mobile version of it and also runs of all the platforms and has a web version too. It is also able to do all the features the modern "second brain" note-taking apps offer.
Personally, I've used our tool Hypernotes (https://zenkit.com/en/hypernotes/). It released with a mobile version of it and also runs of all the platforms and has a web version too. It is also able to do all the features the modern "second brain" note-taking apps offer.