Permit installation of your app outside of Shopify App store

[riddleydiddely]

I have a web application where I have integrated with different e-commerce solutions (Shopify, Klarna, Adyen, Woocommerce etc). I want my clients (who are merchants) to be able to go into my platform and grant me access to their data by clicking a button.

Now to do this with a Shopify app it has to be a public app (since I don't want to do this for just a single merchant). But for them to actually be able to install it it has to be listed as a public app that can be installed on the Shopify app store. But I don't want that, how do I get around this issue? or have I missed a point here?

The image below illustrates when I try to install the app on a store that I don't own or is production store. It's in Swedish but basically says:  

This app must be reviewed by Shopify before it can be installed. Contact the app developer for more information.

[michaelg47]

Any luck with this yet? As far as I know it's impossible, but I hope I'm wrong.