Trekmates' Chamonix Gore-Tex Mitts are a great Mitt at a great price with the Gore-Tex guarantee of waterproof and windproof protection.
Trekmates says:
Classic GORE-TEX mitt with + Gore active technology for increased breathability and performance.
Trekmates' Chamonix Gore-Tex Mitts are durably waterproof and breathable giving your hands reliable and long lasting protection from wind and rain. The Chamonix Mitts have a fleece lining with finger separators providing warmth as well as weather protection.
The thumb and top of mitt are touch screen compatible but performing your task on your fun would be a challenge. There is a stretch panel in the middle of the palm improving the dexterity of the Mitt. The Mitts can be clipped together when not in use so you are less likely to lose one.