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?

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.