If you were paying attention, you surely noticed that this piece moves exactly like the King! The only difference is that the WF is an ordinary piece, not subject to check. Because it is not "Royal", it can be called the "Commoner".
This is a very short-range and very flexible piece that is much weaker than a Knight in the opening, very strong in the middlegame if it can occupy the center, and almost always wins against a Knight or Bishop in the endgame.
Yes, that's right. An endgame such as K + WF + Pawns versus K + B + Pawns is almost always a win for the WF. Not only that, but the Pawnless endgame of K plus WF versus King is a forced win.
The weakness of this piece is that it takes a long time to get from one section of the board to another; for example, in the opening, it takes 2 or 4 moves to get a WF properly developed. Its strength is that it concentrates a lot of striking power in a small area.
The Queen is nothing but a W7F7, of course, and the other possible variations (W1F7 or W7F1 or W3F3) of its move are all quite interesting.