Standard calculator your phone comes with but has a memory you can scroll through. The memory feature-you will lose your place and will spend more time trying to find where it recorded your numbers than if you just typed it all again to check your numbers. The free version has youtube ads where it plays a loud Video that you have to wait 5 seconds to skip...and it will do it randomly while you are typing so you lose your concentration. I wouldnt pay for this. Spent two years with the app as my daily calculator (Im a service tech) and now I cant stand it. Standard Apple products, updates that downgrade.