If you want to live-tweet Game of Thrones from an iPhone while keeping your snacking hand free, you have a new option. Microsoft's Word Flow keyboard has arrived to rival Apple's iOS, after the software giant teased it earlier in the year. The Windows Phone version is generally well-liked, but iPhone and iPad users will actually get more options. The one-handed "arc mode" is curved to be more suitable for thumb use, for instance, and you can select a custom photo to use as a background.