I was in Park Guell in the middle of the heat of Barcelona. The park is quite crowded. Some parts are beautiful, but if you want to go to Gaudi House or other attractions there, you have to pay extra, which is quite not worth the money. I think this park is overrated. But overall, the app was very helpful, and I wasn't on the line when I was there, so they scanned my QR, and I went directly inside. Do not forget to drink lots of water and bring an umbrella because it is going to be super hot up there. Take the metro and then a bus, which stops directly in front of the park. Walking from the city center isn't the best idea. You can take bus number 24 from Placa Catalunya, if I am not mistaken.

Very comfortable, quiet and clean park in Barcelona

Voucher was issued than cancelled, so we didn’t see park guell at all. Still waiting for the money back.