Ovulation calculators worth using?

[faithatkins]

Hello all! Me and my husband started trying for a baby last cycle and I was wondering if it's worth just going and letting nature do it's thing, or to give myself a little advantage in timing? We've mutually decided to stop using protection as we're in a good position to have a child, but don't want to make sex a chore. This ovulation calculator caught my eye (pink is definitely not a weakness of mine!! ), but how accurate/useful is it when compared to tracking ovulation when compared to other methods?

Thanks!