MXTNote is a free PDF reader and note taking app, its a management system with emphasis on links and cross reference.
The basic objects are grouped into the following sections
📌 Simple note can be embedded to notebook to add more details
Links can be created automatically when you reference something from your notebook to original documents. Additional links can be created link in the simple notes layer to capture more relations.
You can choose to work completely in offline mode, or, in online mode, your PDF and notes are synced and accessible in all your devices(In online mode, if you lost internet it will buffer your changes and sync later)
MXTNote is available as web app and android/IOS app. To use web app or mobile app in online mode, either sign up with free MXTNote account, or Sign in with google/apple.