Your SSL certificate is invalid: https://koans.heroku.com/ edit: this works thou...

aikah · on April 2, 2015

I confirm, google complains.

    NET::ERR_CERT_COMMON_NAME_INVALID

    Subject: *.herokuapp.com
    Issuer: DigiCert SHA2 High Assurance Server CA
    Expires on: 19 mai 2017
    Current date: 2 avr. 2015

jonaldomo · on April 2, 2015

heroku charges $20 a month to allow a SSL certificate for a custom domain!

nateberkopec · on April 2, 2015

Just use Cloudflare. It's free.

psychometry · on April 2, 2015

Details: https://robots.thoughtbot.com/set-up-cloudflare-free-ssl-on-...

There are some downsides to this approach that are described there.