Not a "tool" as such but an account with Skrill is definitely something you'll want to add to your armoury against the bookies!
What is Skrill? - Skrill is basically an e-wallet but specifically for use with bookmakers. With Skrill, you can deposit and withdraw into and from your various bookmaker accounts much more quickly than using your normal bank account.
Withdrawing funds from a bookie into your bank account typically takes 3-5 working days but with Skrill you're talking a few hours - sometimes twelve but sometimes even one - the average withdrawal time is usually somewhere between the two, though.
Having an account with Skrill just allows you to keep your betting cashflow actually flowing so you've always got funds available should an unmissable offer arise on one of the bookie websites.
Skrill is completely free to use and very easy to set up. Get yourself a Skrill account today. You'll be glad you did.