Agreed. I have had many arguments with people concerning physical calculators and calculator apps. But despite what people say, they actually use apps when on the move. They may have a real calculator on their desk (i do too), but the truth is they don&#x27;t want yet another gadget in their pockets to worry about.<p>These small RPN calculators are neat, but they fall between two goals. For a physical calculator they&#x27;re a bit too small and fiddly to use. I certainly wouldn&#x27;t want to program on the actual devices [although i really would like to be able to transfer programs in&#x2F;out from a PC]. The size of the originals was about right - nice to handle and also pocket sized.<p>The other goal is portability, but in this respect they are _still_ another thing to carry. and it&#x27;s not that clear whether a tiny keyboard is actually better than a large smartphone screen.<p>here&#x27;s a plug for a calc app i wrote (sorry not RPN). It&#x27;s totally free with no annoying adds (so i feel ok posting it here).<p><a href="https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=com.voidware.retrofree" rel="nofollow">https:&#x2F;&#x2F;play.google.com&#x2F;store&#x2F;apps&#x2F;details?id=com.voidware.r...</a>