Other regions such as Japan and Brazil are catching up as well, the company said.Fon's improved coverage has largely been possible thanks to deals with operators such as BT, Deutsche Telekom, SFR and Belgacom in Europe and Softbank in Japan.Recently, Fon has started to take aim at the U.S. In September, it signed a roaming agreement AT&T, which allows customers of both companies to surf via Wi-Fi