Used it on Fantasy last week. It has information regarding the dining room menus, character meets, movie/show times and activities. Activities were also broken into youth club activities (with various divisions for different clubs), adult and family. You can mark an activity as a favorite and it will give you a reminder. You can look at the current day or future days. What I really liked is that it would also tell you when that character would have another meet, and other times (if applicable) for the activities and shows (that day or another day). That way you could plan in advance, and you would know if that is the last opportunity to see a certain character or if there would be other meets. You could also chat with other uses, kind of like text message. DH did not use his much so we did not do much chatting, but I used mine all the time.
You have to make sure you download the app before you leave and then when you get on the ship put your phone on air plane mode and turn Wi-Fi back on.