Some maps that I creat in ArcGISOnline doesn't show up in collector. I gave the same sharing permission but to no results. I can see the map on ArcGIS when I search for the given map and can view them.
Have the maps got an editable layer in them? I think that's a requirement for Collector.
Also I've found sometimes you have to sign out of Collector and/or restart (remove from background process in iOS/Android) Collector for new maps to appear.
