Hi David Lednik. This should not be a secured layer; the following should work:
AGSWMTSLayer.wmtsLayerWithUrl(NSURL(string:"http://opencache.statkart.no/gatekeeper/gk/gk.open_wmts"), title: "topo2", imageFormat: AGSImageFormat.PNG24, tileMatrixSet: "EPSG:32633")
But, upgrading to 10.2.4, I believe the issues I saw no longer occur. If i do find any more though, I´d be happy to share my project. If you have a BitBucket account, I can share it if the issue reoccurs.
Thanks for looking into this!
Kristoffer