Within the post: Windows 10: A Store That’s Ready for Business, Microsoft is mentioning the following: 'with Windows 10 we will deliver one Windows Store for all Windows devices'. But therefore the new web-based Store portal must be used. They will become visible in the Windows Store at a later time.
First you need to create a new Business portal on businessstore.microsoft.com and sign in with a work or school account, or Azure account if you prefer. In the Windows store on Windows 10 devices this account is used, next to your Microsoft Live ID. In that case a new tab will be present (next to Home, Apps, Games, Music, Movies & TV). This based on the company name used during creating the Business portal.
When adding apps you can choose between: 'Add to your private store where all people in your organization can find and install it', or 'Assign to people' only. That way they won't be present in the private store, but only for specific people. Last one is 'Distribute later', which isn't a deployment at all, but can be done later.
In this case I added apps to the private store, where all people in your organization can find and install it. Unfortunately the app is not ready for deployment yet, but 'Add in progress' is shown.
When adding apps to the Business portal, it can takes up to 24 hours for the app to get present in the Private store. When looking on Windows store on Windows 10 (full edition) or Windows 10 Mobile the same apps are there.
As mentioned earlier; When signing in with your Azure account (or add it next to your Live ID) a new tab in Windows Store will be present. This is how it looks like on my Surface (5 apps, but 6 deployed).
And this is how it looks like on my Phone (4 apps, where 6 deployed). For it seems LinkedIn and Translator are Phone only, Sway and Buienradar are Windows (full OS) only.
So unfortunately the same story as before (using the Company portal). Where does this fit in the One unified app store across devices, One great experience model, when apps differs between Windows 10 and Windows 10 Mobile devices? Because Microsoft is saying it's one platform, I hope this will be more clear in future..
Hope things will get more clear this way!
Update: It's possible to use 'My Library' too, and see which apps works and which apps doesn't work on your device.