A zoom lens and telephoto lens aren't the same thing.
"Zoom" is often used in common language to refer as "make bigger", but in photography all it means is that the lens has a variable focal length.
Focal length is often what determines how "close to" you are to your subject.
A telephoto lens is one with a long focal length (>100 mm focal length), which makes your subject appear close. A wide-angle lens (which fisheyes are part of) is one with a short focal length (<20 mm focal length). It's the opposite of a telephoto, your subject appear as if it's distant and you see the landscape around you very well. Lenses that fit in between those two categories are standard lenses and are the most popular ones.
Having a zoom lens only means that you can change how close you seem to be to your subject. It's independent from the focal length category of your lens. For example you could have a zoom telephoto lens, or a non-zoom telephoto lens (a prime lens).
For example, the lens on a iPhone is a prime lens since it doesn't zoom. The zoom feature is 100% digital as the lens doesn't actually move to change focal length. Point-and-shoots, on the other hand, have zoom lenses.
Ollocip offers a
telephoto lens for iPhone which makes your subject appear closer, but it is not a zoom lens. That means you won't be able to choose exactly
how close to your subject you want to by playing with the lens itself, but you'll still be able to do the usual pinch-to-zoom on your iPhone screen (digital zoom).
Unfortunately the Olloclip telephoto lens only offers a 2x magnification and it's pretty expensive for what it is ($100). If you're serious about photography you may want to invest in a cheap/used DSLR instead, but of course you wouldn't have the portability and overall convenience of an iPhone.
Hope that helps clarify a bit!