The ornamental design for a flexiblepouch, as shown and described.
1. Flexible pouch
1.1 : Perspective
1.2 : Bottom
1.3 : Side view
1.4 : Top
1.5 : Front
This design is intended for the simultaneous storage of two different products; the broken lines, showing on the top of the flexible pouch, are included for the purpose of illustrating portion of the flexible pouch and form no part of the claimed design (disclaimer); the bottom of the flexible pouch has the shape of an elongated oval (bottom view); in the middle of the elongated oval, there is a line that divides the flexible pouch on two parts to storage two different products.