We had a great stay at Cris app. The flat is spacious, very clean and have everything we need for our short stay. Internet is great and Chris also provided us mobile internet which is super if you all the time outside the flat. Location is excellent. Near Acropolis (5min), Plaka(5min) and all other attractions and restaurants are in walking distance. App is a little bit noise at night because of the very busy street, but we slept like a baby. Chris was very welcoming, we had a great communication.
I would definitely recommend Chris and his app to everybody who is planning the trip to Athens.