Gerardo,
              That would be because this is an NVDA add-on, and, thus, only for the PC platform.  The developer's e-mail address is listed on the very webpage you make reference to, and contacting him would be the appropriate next step.  I very much doubt that there is a version of this for iPhone, but only he can answer that.
               As a note for the future, general questions relating to iPhone apps are off topic for the group, though I can see why you asked this one specifically, as someone appears to have stated that there is an iPhone equivalent of the NVDA Add-On.  There is no evidence of that at the add-on developer's GitHub page.
--
Brian *-*Windows 10 Pro, 64-Bit, Version 1909, Build 18363
*/Science has become just another voice in the room; it has lost its platform.  Now, you simply declare your own truth./*
~ Dr. Paul A. Offit, in /New York Times/ article, /How Anti-Vaccine Sentiment Took Hold in the United States/ <https://www.nytimes.com/2019/09/23/health/anti-vaccination-movement-us.html>;/,/September 23, 2019