WiFi direct mode

[bill2reg]

I can turn on WiFi direct mode (which understandably disconnects from my home network) and I can connect to a friend's Galaxy tablet, also in WiFi direct mode. They recognize each other and they make a connection. BUT, when I display a photo, for example, and tap the share icon, sometimes there is an option there to share via WiFi direct, and sometimes it's not there. But even when it is there, and I choose it, nothing happens. Has anyone had success in sending files this way? I know there are some apps available, even free ones which is OK, but I would think that the tablet(s) should do the transfers on their own included WiFi direct mode. Otherwise, why have it there?