Katya was wonderful host and helped in all the things we asked about: app, check-in/out, and the surrounding location. she even kept our luggage after check-out and until we needed to go to the airport.
Apartment is located VERY close to the Acropolis Museum (4m walk) and all the cool side streets around it. I dropped the rental car back to the airport and returned by train immediately on arrival, as parking in the center of Athens is not simple. This was a very good solution.
Thanks Katya, I'll definitely recommend this place to all my friends.