Can I create or manage a Facebook app via a 'business' account?
When I try to access https://developers.facebook.com/apps
when logged in as a business account it redirects me back to my homepage and won't let me create an app.
Context: A business / advertising account (sometimes called a 'gray account') is a special, now-deprecated type of account Facebook provided to advertisers to manage their Ads and Pages before Business Manager launched - the primary reason people want to use a business account with an App is to link the existing App to the Ad account so Ads can be driven to the application.
Is there any way to manage or create a Facebook app using a business / gray account?
'Business' or advertising accounts can't manage apps - if at some point in the past you were able to create an app using a business account this was a bug or loophole and shouldn't have been possible - only real verified user accounts should be able to create and manage apps.
It's also possible to have a Business account which owns apps if you created a fake user account, created apps, and later converted your user account into a business account or had Facebook do it for you.
You can do this by making all of the admins/developers working on the app developers or admins directly via the API or the 'Roles' tab of the App settings:
You can specify which business accounts will manage the ads for an app in the app settings on the Advanced tab - add the email address used to manage the ads.
This is the only supported connection between apps and business accounts.
Screenshot below: