Notabula works in any modern browser, on your computer and on your phone. There is nothing to install for that.
Windows
There is an app for Windows 10 and 11 (64-bit). Download it at notabula.com/en/download. The app updates itself. Windows may show a warning the first time; the download page lists the check code (SHA-256) you can use to verify the file.
Android and iPhone
The apps for Android and iPhone are on their way. Until then you use Notabula in the browser on your phone: everything works there too, with its own buttons for what a right-click does on a computer.
Browser
Use a current version of Chrome, Edge, Firefox or Safari (from version 16.4).