Recent developments in wearable robots and human augmentation open up new possibilities of designing computational interfaces integrated to the body. Particularly, supernumerary robot is a recently established field of research that investigates a radical idea of adding robotic limbs to users. Such augmentations, however, pose a limit in how much we can add to the body due to weight or interference with other body parts. To address that, we explore the use of soft robots as supernumerary robotic fingers. We present a pair of soft robotic fingers driven by cables and servomotors, and applications using the robotic fingers in various contexts.