Where can I download the Manage Signatures App (desktop app)?
You want to install the desktop version of the signature management app (Manage Signatures App). You can't find the installation/download link.
The desktop app is now deprecated. Use the web-based signature management app instead - all your rules, templates and settings are already there. It is a modern solution which does not require any local installation and can be used on any device and platform (including Apple devices).