Abstract: A holster and methods of use are provided for storing a smartphone or other electronic device of a user in motion. The holster includes a protection pocket with an open top end configured to receive the device. The holster also includes a closure flap disposed adjacent to the open top end and configured to move between an open position in which the device is exposed and a closed position in which the device is fully enveloped within the protection pocket and the closure flap. The holster may further include an adjustable flap fastener configured to secure the closure flap against the front surface of the protection pocket at a variety of heights to accommodate different device footprints, and an adaptable attachment mechanism configured to selectively secure the holster in an attached configuration upon the user's appendage or an article of the user's clothing. Other embodiments are also disclosed.