It's all too common that plastic flaps on various devices and storage containers break off.
Over time, the thin plastic hinge gets weak from repeated use, and snaps. A common place this seems to happen is on pill containers, since they are typically opened and closed at least once every day. Another common place is on cell phones, tablets, and digital cameras that have plastic flaps protecting their ports.
Is there a life-hacky way to fix this when it happens, or prevent it from happening in the first place?