At $9.99 Raiders of the North Sea offers a really solid gameplay experience in a well put together package. I would say the primary audience for this app, like most board game apps, is the travelling board gamer who isn't interested in lugging their entire collection along with them. We need to see more board game apps like this one. Not just that prime target is satisfied, but also a wider array of folks with features like online play and a simple and easy to use interface. If you like board games that emphasize strategy over randomness or board games that feature vikings, or just worker placement games, this is a great one to pick up.
Raiders of the North Sea Digital is a beautiful and fun implementation of a great board game. With the simplicity of placing and removing workers, and quick AI games are short. With a few additional tweaks to the interface and gameplay, it could be even better. Thankfully Direwolf has already released some improvements and is continuing to work to make the game as polished as possible.