Yes, we need this trope, but it needs a much better name. "Killer App" has a more mundane definition we need to catalog, and most of your examples have nothing to do with violence or causing death, which one would expect from the name.
Topic on Talk:Metaphysical App
Alright, I changed the name to something less mundane. Does it work?
I like "Metaphysical App". I wish I'd thought of it.
Just preface "Literal" to the current name.
I was trying to be clever with the title. I used Killer App in reference to the term 'killer app' about an application or some piece of software whether a program or game is so popular and essential that one would buy the hardware to use it. Then there is the word 'killer' as in the slang term which is used as an adjective for someone or something that is cool, impressive or exciting which the apps in the examples shows. It wasn't supposed to tie to death per se but some of them are capable of it.
So it's a "literal Magical Computer" variation of Magitek, but specifically for smartphones? IDK, perhaps it's distinct enough, in that it's specifically combines properties in a meaningful way. Also, do other cellphones and portable computers count, and if yes, which sorts?
Well, it more about the applications that can be usually downloaded onto a smartphone but other technology can download the same apps. The different pieces of media usually shows smartphones being used for the app but it there is an example with another device then it should fit the trope.