The unique selling point of the Classic Calculator app for Android is that it provides the actual UI of several famous and classic calculators. It shows an actual photo of the classic calculator model as the UI. This seems a bit tacky, but is quite functional once you start using it.
The Andromeda skin in this app is exactly the first scientific calculator I ever used. It was a clone of an older Casio calculator built and sold by Ajanta in India. Money was tight and I had bought this instead of the Casio calculators which everyone else had since it was almost half priced. The buttons were small and shaky, but it got the job done for several years. After I lost it, I bought a more contemporary Casio scientific calculator, which appears in this app as the Pegasus skin. I was quite delighted to discover both of the calculators I used in this app.
Note that the app is very heavy, it takes a while to load up. It shows ads, in fact your first click after loading the app will display an ad. So, I can only recommend this app for only those people who really miss a particular calculator which is available in this app as a skin.
Tried with: Classic Calculator 1.1.95, Android 5.0.2 (Lollipop) and Moto G 2nd Gen (XT1098)