An App that simply displays your Power To Weight Ratio would be really cool. As well as another App that displays your current Realtime power output without a bunch of debug/extra information would also be handy. Would be nice to see the effects of a bad overrev to determine how bad it really is. Kinda funny too.
When you're choosing a car in the car list, then on the right side in the Performance tab it will say the power to weight ratio. The only downside is that it works for configs that have a .json file There are such apps already, just look harder on the app list