A very useful site for the backcountry in Europe is Wepowder.
Weather updates whenever there is pow. A powfinder app that actually works. Wepowder Lines: an apllication that shows you the best lines in each resorts uploaded by users. It’s really as simple as going where they tell you to, and you will always ride fresh pow.
For people who understand Dutch, the dutch site is a lot cooler with lots more in depth info (buy the book if you read dutch, you’ll thank me later)