OK — been using this thing for something like a few months now and it's basically bookmarked at this point, so thought I'd write something up since a mate asked me last week. Am based in the UK, mainly stick to footie and the horses, nothing mad, so take it how you like.
The reason I started using it was genuinely embarrassing — I couldn't ever figure out what an ew return would be once you get five places instead of three. I'd just wing it and moan when the payout landed. These days I stick my stake in before every slip, even a straight one-selection punt.
Their single bet calculator tool is the part I'm on daily — you put in stake and odds and you get profit and total return with no faffing, either odds format. It also handles the multiples — trebles returns, lucky 15 and lucky 63, yankees, and that's where I'd always lose track. Have a go yourself, it lives at risk free bet calculator — free, no signup.
One thing that really shifted things for me were the geekier extras. The odds-to-probability calculator that shows how much the bookie's taking, plus a kelly staking tool — I stick to fractional kelly as the full version is terrifying. The dutching one gets used a fair bit when I'm spreading across selections.
Couple of gripes. Its interface is very functional, let's say — zero flash, it's clearly function over form. On my phone it works although the acca grid need a bit of scrolling. There's no proper app, just the site — slight shame but worth saying.
So yeah. Free, not plastered in adverts, does what it says. Anyone who honestly does the maths on paper, give it a go — saved me a load of "wait, that's it?" moments.