Yes it will.
It is the Blackberry Unlimited UK Bolt-on,and is free with Simplicity tariffs of £20+.
(Which i believe is stated as being £19.something currently)
On the lower price plans its £9.something a month, which works out more expensive than being on £20 tariff with it for free.
"That's it then. Cancel the kitchen scraps for lepers and orphans, no more merciful beheadings... and call off Christmas."