Nice concept! Although most of the techniques were already used before in this contest. I really like the check-in method. This will surely be convenient for a lot of visitors. I think though that there's still some more potential in connecting all the visitors of the hotel. I miss the details a bit on how the platform would stimulate people to network more.
Althought Jeroen is right about you portraying ideas already used in this contest, I like the part where other users can upload their own pictures to the app. This is a great opportuniy not only for interaction, but for seeing the city from different points of views.
Thank you very much for your feedback.