The Intel Core i7 processors are simply too powerful and too resource intensive to be used in most mobile devices, especially phones. ARM 7 and Snapdragon processors use specific mobile friendly architectures, which makes them more common in mobile phones. You may however find Intel Core products in larger tablets and laptops.
Intel Core is Intel's brand name for various mid-range to high-end home and business microprocessors. These processors displaced the existing mid-to-high end Pentium processors of the time, moving the Pentium to the entry level, and bumping the Celeron series of processors to low end. Identical or more capable versions of Core processors are also sold as Xeon processors for the server and workstation markets.
As of 2016 the current lineup of Core processors included the Intel …