The latest version of Zotero, Zotero 7, fully meets the Web Content Accessibility Guidelines (WCAG) 2.2 Level AA. This ensures functionality is accessible to screen-reader and keyboard-only users. Please note that this applies to the desktop version of the application. More information can be found here: https://www.zotero.org/accessibility.
Text to speech: https://forums.zotero.org/discussion/116141/announcing-zotts-a-text-to-speech-plugin-for-zotero
Open PDF in external reader: https://github.com/retorquere/zotero-open-pdf
More plugins: https://www.zotero.org/support/plugins
Zotero for mobile devices: https://www.zotero.org/support/mobile