I've used this calculator app for several months, really love it. It has a back delete button to erase just one number and not the whole thing. No ads, comfortable and easy to use, has a history, many options available, very intuitive. Congratulations to the developers. Update: Has been my favorite calculator. Exactly what I needed. I’ve used many different calculator apps and this one is absolutely the best. I can change the button size and the font size, love the customizable options, beautiful interface, I love the way it has a history, allowing me to see any possible errors, I can see everything I calculate. I use this calculator almost every day, it has everything I need! Update: Have used the app for 3 years, on my iPhone and my iPad, works great, practical and easy to use and no advertisements popping up. This app helps me a lot, it’s like the best thing ever.Again just the best calculator. Thanks for making the app.

I recently purchased this and have been very pleased, especially since I have been through many, many other calculators and always deleted them when they said they were free, but when opened there was always a surprise significant charge after a few days or weeks. I really needed the history, but not all of the frilly bells and whistles. I was surprised to find that now I can even save histories (and delete them) under specific projects or dates and it even has single space backup/delete. Then, I was blown away to find a lifetime license that was very affordable that adds even more features!

With no documentation and no other means of contacting the developer for guidance, I was forced to initially post a negative review in the hopes of getting some feedback as to how some of the features were supposed to work. After reading the developer’s subsequent feedback, I at least now know what the “diskette” and “folder” icons are supposed to do (see developer’s response — spoiler alert: tapping the “folder” icon will create an archive of all of the calculations that were on the screen, and the blank input screen you see is simply for entering the title you want to give that archive.) So, all in all, except for a few quirks (eg. adding a title to an individual calculation inserts it below the calculation instead of above?), it really is a pretty useful calculator. Now, if only there was a way to paste in values or expressions, or go back and edit a calculation you previously entered, that would be really helpful.

The only annoying thing is that on my ipad all the numbers and operation symbols display with an underscore. This is strange and makes the equal sign look funny. Still it is my favorite calculator for the ipad and I use frequently.The developer correctly pointed out that the problem was my system setting. However because I need the accessibility setting turned on. I believe that all accessibility setting should be taken into account when designing an app. Those settings were put there to help people who have problems with the system default settings. This setting displays the chosen field as a button so that people who have trouble touching the screen will be able to touch the correct spot to activate the desired field. Without this it is difficult to see where the edge of the field is on the screen.