Hi Kzafarullah,
My household doesn't have iPhones, but we do have older Macs as well as Linux machines, so I googled HEIC. I found this. It might be useful in general, until the rest of the digital world adds HEIC. Now I have to find an application that will let me convert HEIC, since I am sure I will be getting them from people. So I, at least, am glad of your "head's up"
Zephy