I have got 6 applications on Qlikview Accesspoint, but I can share only 1 application. For others, I don't have this option in tools bar. Is there an option somewhere to activate or not the sharing for other people?
Yes. In the management console, go to Documents --> User Documents and click on a document. Go to Server --> Availability and make sure "Session Collaboration" is checked. Then click apply. You will have to do this for each document you wish to share sessions for.