Check out my latest running calculator app. Tiny app, super fast and a modern design. Its a race calculator, equivalent performance predictor and gives you your racing splits.
https://play.google.com/store/apps/details?id=com.calculator.running&hl=en
Comments
Android only I'm afraid
One thing you could change is the option of entering your weight in stones and lbs.. for example '11 stone 10lbs' instead of number of lbs. Not many people know how many lbs they weigh, but know their weight in stones and lbs.