[Question] What (feasible) augmented senses would be useful or interesting?

The BrainPort is a device which allows blind people to have their sight restored (partially) by sending signals through electrodes that rest on the tongue.

The signals are sent to the tongue via a “lollipop,” an electrode array about nine square centimeters that sits directly on the tongue. Each electrode corresponds to a set of pixels. White pixels yield a strong electrical pulse, whereas black pixels translate into no signal. Densely packed nerves at the tongue surface receive the incoming electrical signals, which feel a little like Pop Rocks or champagne bubbles to the user.

Seiple works with four patients who train with the BrainPort once a week and notes that his patients have learned how to quickly find doorways and elevator buttons, read letters and numbers, and pick out cups and forks at the dinner table without having to fumble around.

- Scientific American

The brain seems to be remarkably good at reinterpreting sensory signals. What possible applications are there of this, especially which might be practically implemented by an average person today without needing to develop specialized hardware?