A drywall trim application device that can hold a large role of drywall flex corner trim material and, as the material is being dispensed, pre-crease or form the material for use on an inside or outside corner, or any angle within the range of the trim material, apply a mastic material (drywall mud, adhesive or any other bonding medium) to the flex trim material, and cut the material at any desired length automatically. Measurements may be either input by hand or downloaded from an electronic measurement tool into this device. This invention can generally store multiple measurements such as length and angles, measure the length of flex trim material as it is dispensed from the device, crease the material, apply predetermined amount of mastic, and automatically cut the flex trim material to each length previously input.