Google Play alternative for android app distribution

I have an android app that is a counterpart to our software product that we sell to customers.

When we sell our product to a company, I need an easy way to give those users access to the app, including updates, product description etc.

The reason that a service like Google Play will not work is, that different customers require different versions of the app depending on their version of the main software.

Some customers are unable/unwilling to stay up to date, and we need to be able to give out different versions of the app depending on their version of the software.

I thought about creating different apps on the Google Play store, each with it's own version. But I don't want to have to duplicate the product description,screenshots, etc for each app.