Are private or password-protected apps acceptable in the Apple AppStore?

Simple qu开发者_开发百科estion - can I put an app in Apple's AppStore which is only functional for those who have a username & password? This is for a client who wants to distribute their app only to a select number of people. The Enterprise license is not an option, and while ad-hoc distribution is, I'd prefer to go through the store.

As the material is semi-sensitive, I'd need to keep the description to a minimum (eg. this app is only for XYZ users, and requires a password), and screenshot to just a single screen of the login page.

Does anyone know of any apps in the store like this?

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These apps are more readily rejected, but Apple doesn't explicitly disallow this. You will have to provide them a test login during the application approval process.