Climbing could use a few. Something that could give you diagnostics as you go rather than just the simple change in altitude. Maybe a Bluetooth connection to your belay device? Although I'm not sure if having more moving (or digital) parts in a grigri or whatever is wise.
Hiking and mountaineering could have something to help you plan your pace when at high altitude.
General outdoor tools like helping you ration your food and stove fuel and water and what not.
Typically these sorts of chores are done mentally but a backup system to keep you sharp couldn't hurt?
No idea! It might, but I've never heard of it before.