Right — been using this thing for something like five months now and it's basically bookmarked at this point, reckon I'd write something up since a mate asked me last week. I'm in the UK, generally bet football and racing, a fiver here and there, for context.
How I found it was actually a bit daft — I never could get my head round what an each way payout would be with 1/5 odds a place. Basically I'd guess and moan when the payout landed. Now I type the odds in before I place anything, even the boring singles.
Their single bet calculator is the part I use most — you drop in the price and your stake and you get returns with no faffing, fractional or decimal, doesn't matter. There's also the bigger stuff — trebles maths, lucky 15s, patents and yankees, which is where most people I know mess it up. If you fancy a poke about, it's here matched betting tool — free, no signup.
The thing that actually shifted things for me was the nerdier bits. They've got an odds-to-probability calculator that shows how much the bookie's taking, plus a kelly staking tool — I stick to fractional kelly because full kelly is far too aggressive. The dutching one is handy too if I'm covering two or three runners.
Couple of gripes. Its layout feels a bit basic — no polish, it's clearly function over form. On mobile it's fine although the bigger tables are a squeeze. And no proper app, it's a website and that's it — fine by me but you asked.
So yeah. Free, no ads shoved in your face, does the job. If you still works out returns on a calculator app, try it — saves me a fair few dumb bets I'd have regretted.