The Danger Hiptop, also branded and sold as T-Mobile Sidekick, is a mobile smartphone and communicator series that was produced by Danger, Inc. from 2002 to 2010, developed in close partnership with T-Mobile US and with most models manufactured by Sharp Corporation. The Hiptops were designed to be held horizontally with both hands, allowing typing with two thumbs on a QWERTY keyboard that is revealed by a 'flip out' display rotating 180 degrees on a hinge pin. They ran on a cloud-based, Java-made software synchronizing with back-end services provided and maintained by Danger, holding personal data and offering services such as email, instant messaging, and a catalog of downloadable apps.