The London Pass is on sale through Friday at 15% off. A few cautions. You should price out the attractions you are planning on seeing to make sure the London Pass is a good bargain for your particular trip. Sometimes it is and sometimes it isn’t.
In addition, the best bargains are the multi day passes. The price only goes up a few pounds for each day.
I have used the London Pass in the past and found it provided time and money saving for my particular itinerary. Each person should price out for themselves.