Google+ for android is fully touch based that means it does not need hard keys to access. It can b fully operated with screen touch. It shows that Google is totally focusing on removing the dependency of physical keys. As you can see on Galaxy nexus, there is no hard button, even iphone too has one physical home button. Galaxy Nexus is android 4.0 based device which shows Google's ideas 'bout touch tech. In android developer's recent post it was announced that Androids after Honeycomb 3.0 will not contain hard button support and will feature an Action Bar. This change will really help to grow touch technology.