January 28, 2015:

The app doesn’t work unless you’re willing to make your gmail account “less secure.” After installing and entering my gmail account & password, this said it was “unable to authenticate with the current session’s credentials” and I got an email from Google titled “sign-in attempt blocked.” Apparently this app doesn’t meet Google’s requirements for being secure-enough to be trusted to access Gmail accounts. In your Gmail account, you can turn off that security check to allow this app to work, but I’d rather see this app update to jump through whatever hoops Google requires than flip some switch in my settings that says it makes things less secure.

RobUSA about Mia for Gmail