I was using “Reign Win8/WP8 Support” in the past, however they seem to have stopped supporting it and it no longer works with latest Unity builds.
I am now evaluating Prime31. It was not obvious they had support for WP8/Win8, since they don’t have it in the asset store. You need to look at their web site http://prime31.com/. Down side is they are really expensive.
$40 is really expensive? You should make that back in the first day. I am of the school of thought that if it takes me more than an hour to implement then $40 is really pretty cheap.
In general I agree, which is why I purchased the single “Reign Win8/WP8 Support” asset in the first place. For $30 I got MS Ads, IAP, and some basic support for both WP8 and Win8.
To get the same using Prime31 I would need to purchase multiple packages for a total of $295, that is very expensive. Even more so when you consider there is no source code included. Normally when packages are that expensive you get source code with it.
So my plan is to use Prime31 for ads, and use BFS for IAP (which I found before Prime31). The other stuff I have since coded myself.