Only one app access in a stream

Hi Everyone,

I hav a stream which has 4 applications App1,App2,App3,App4. And i have 4 users U1,U2,U3,U4.

I need to provide access to each for only one app.

U1 - App1

U2 - App2

U3 - App3

U4 - App4.

However i cannot place these app in four different streams. Is it possible to restrict users to access only one app ? If so then how can i achieve this?

Thanks,

Partha K