Thanks, I found the mistake. Sorry for you that I use the other app and they made a little copy of your map, but I found them first half a year ago, and now I found you(I searched for "wind" in the google-play store). The first app I found was windfinder. At the moment a think for my use ist teh windy app, sorry when I say that, but it is a little bit more compact and gives all the information you need for sailing at a lake. the point with the pro and normal version at this tim I think you are right, the difference is very low.
regrads from Germany