vault app of my mob is not showing in desktop why?.

@gullu: I'm not sure I understand what you're asking. Are you having trouble setting up 1Password for Android? Unfortunately without some basic information it's hard to say what might be going wrong and how we might right it! Please tell me all OS, 1Password, and device versions you're using, the exact steps you're taking, and what is (or is not) happening the way you expect so we can figure out the best plan of action. Thanks in advance! :)