You can save any of the calculations and load them later, share it with free or email to yourself.
Many users gave this app a low rate because not all calculators are enabled in this free version. I can understand but that's unfair to us. Anyway, in the new 2.0 release, instead of prevent you from using some more advanced calculators, we will allow you to use them by showing a full screen ads. If you don't like to see any ads, you can always upgrade to the full version which has no ads, but at least now you can use all the calculators.