I simply aren't able to find the number of applications you are able to host on heroku with one dyno?

I intend to host lots of small applications with little traffic.

Interesting solutions

Dynos are calculated on the per application basis.

However, this does not mean you have to buy 3 dynos to operate 3 applications. You may create 3 application each with 1 dyno.

One Application per Dyno / subdomain.heroku.com.