Absolutely necessary
I used travelwifi for a 7 day vacation in England with my family of 5. With entrance tickets, train tickets and theater tickets all on our USA phones, we never incurred a charge from our American carrier. Yes, public WiFi is available most places, but not all places. And sometimes you have to enter your personal information to access the public WiFi. Travelwifi offered instant access without creating public accounts. My kids also enjoyed playing Pokémon Go during site-seeing. This is the second time I have used this product. I will definitely use it then next time we travel internationally. Thank you travelwifi.