Re: Where have I seen this before?
"nowadays NO ONE NEEDS to use a stand-alone calculator anymore professionally"
I concur that current calculators are poorly designed, but with great respect, I disagree they're unnecessary. Actually, when doing electronic product design on a secure (not internet-connected) computer I regularly use a TI-30 and a 1987 vintage Tandy EC-4014 calculator that does Boolean algebra.
I get worried by the widely made assumption that you can trust an arbitrarily chosen online resource - particularly if it's "free". Any fool can set such a thing up and they do, witness the recent Siraj Raval scandal.
It's been my experience as an engineer that you need to get used to your tools. They all have idiosyncrasies and issues, but once you know them you can usually work round them. On the other hand, there's no warranty that the Whizzo.me online calculator is the same today as it was last time you used it a few days back. It's probably been "updated" and thereby broken in new ways.