They released early today (they are based in Australia):
They are using Spark to provide customers with a lightning wallet. Spark is trustodial (h/t @justin_shocknet) but they've also made the weird choice of making all customer balances and transactions visible via a public explorer as pointed out by @theinstagibbs.
This might not be a big deal if it were hard to determine a receiver's Spark address, but any bolt11 paid to a Spark customer reveals the Spark address. @benthecarman has cooked up a utility to doxx the Spark address from any bolt11 invoice paying a Spark customer.
What this means: if you use WoS (or any other wallet using Spark), anyone you give a bolt11 to (which you do when you want to receive money) will be able to view all of your transactions and your account balance.