Unfortunately, it shows the same data that you can already see in the stock activity app. I am a runner and the reason why I stopped using my apple watch and went back to my nike sport band and sport watch (GPS) is because after you have finished running there is nothing to do with the data. There is no easy way to compare your recent run to previous run, compare trends over a week, month, year, etc. I have been using nikeplus since 2009 and I was expecting no way to import data into the apple system as I know the apple system is very limited. I was expecting at least similar functionality that the nikeplus website has, as that is fairly bare-bones compared to other running sites but it suits my needs.
Maybe a future version of this app will provide better detail for specific activities. Id just like basic stuff like distance, pace and heart rate and a way to compare this data over different time frames to recognize trends. It just shows the running data in terms of "minutes of exercise" which is useless.
The mighty nutmeg about MyTrends++, v1.0.2