Is Mate available for Android and Windows?

Not as native apps. Mate is made for iPhone and iPad, Mac (including a Safari extension), and as a browser extension for Chrome, Firefox, Edge and Opera.

What you can use on Windows and Android today

• Browser extension. Chrome, Firefox, Edge and Opera on Windows, Linux and ChromeOS run the same Mate extension as on Mac. Firefox for Android also supports extensions, and Mate installs there from Firefox Add-ons.
• Online translator. matetranslate.com/translator works in any browser and doesn't need an install.
• Your account. History and Phrasebook synced from your other devices are viewable at matetranslate.com/account.

Why no native apps

We're a small team and we chose to do a few platforms well rather than many platforms poorly. Android and Windows aren't ruled out, but there is no date.