We have no plans at present to replicate all the functionality of Plotaroute in a native app, but we do have a native companion app under development that will provide offline navigation and recording of routes. This is currently in Beta testing with Premium members: Beta Testing of New Mobile App.
I would like to know when a real application will be made, not a plug-in for the browser. It's annoying that with browser restrictions I can't use the "app".