Switch to at least 2x-sized dynos and use nginx-buildpack (https://github.com/ryandotsmith/nginx-buildpack) with multi-buildpack (https://github.com/ddollar/heroku-buildpack-multi).
You'll probably need to modify/fork the ruby buildpack to do asset compiles twice (if necessary) and check-in both apps into the same repo. And of course modify the nginx configuration.
Switch to at least 2x-sized dynos and use nginx-buildpack (https://github.com/ryandotsmith/nginx-buildpack) with multi-buildpack (https://github.com/ddollar/heroku-buildpack-multi).
You'll probably need to modify/fork the ruby buildpack to do asset compiles twice (if necessary) and check-in both apps into the same repo. And of course modify the nginx configuration.