Even though I really like BetAngel for its professionalism for Mac users like myself that are only interesting in trading with a ladder interface, I recommend BinarySoft DBI. It will do all you want if you don´t need the advanced features that you can find in BetAngel, you just have to get used to the binary method of trading. You can even configure the way the ladder works too, plus you can see the equivalent Betfair prices as tooltip popups in the ladder.