It’s very convenient to have this in the menu bar, especially on the big iMac, as the the little default calculator gets lost amid my windows. I am not a math person and so to have a quick way to add (you laugh but I am dyslexic with numbers), calculate percents for discounts (the way I think) etc is great. Nice that it has a “paper tape” type menu, so I can take a quick look back in case I need it. I use it now every day. I reported a little bug to the developer and heard back from him right away, I am sure it will be fixed in the next iteration. I think it’s worth the money!