WOW is an Icelandic ultra-low-cost airline with their main hub in Reykjavik (KEF). WOW was on the edge of insolvency, so I would avoid flying them.
Summary: I have never flown WOW, but my impression from reading about them is to stay away unless there is a really amazing deal. The fees are very high and the service is subpar. Also, if you follow our Flight Deals, you can likely find a better deal with a major airline when you factor in all of the fees.
Airline Website: WowAir.us
Long Haul Fees: (Depends on Route): Carry-on bag ($40), seat selection ($10), checked bag ($60), meal ($10-12), non-alcoholic drinks ($3), alcoholic drink ($7-10), snacks ($3-5).
Comparing prices to regular carriers I would add: Carry on only: $140 round-trip or Checked bag only: $180 round-trip
Routes: Route Map
North American Cities: Boston, Detroit, Montreal, New York (EWR), and Toronto.
Seat Maps by Plane: SeatGuru
Menu Prices: You can expect to pay $10 for a meal or sandwich, $5 for a snack, $3.29 for water or soda, and $8 for a beer (here is the 2017-2018 menu).