Should we trust "MyMail-crypt for Gmail" Chrome extension?

[ankostis]

Hi,

I'm wondering whether this open-source Chrome-extension for GPG on GMail[1]
is to be trusted; I mean, not to call home with my secret-key and passphrase.

I searched through the mailing-list archives and found only one
reference from 2014:
https://lists.gnupg.org/pipermail/gnupg-users/2014-April.txt

This extension is the only alternative to use GPG with gmail in
corporate environments where SMTP ports are blocked (unless we
consider as an "alternative" to manually clear-signing each message
text to be sent with cmd-line).

With kind regards,
  Kostis

[1] https://chrome.google.com/webstore/detail/mymail-crypt-for-gmail/jcaobjhdnlpmopmjhijplpjhlplfkhba