Sony has unveiled the new IMX586 imaging sensor for smartphones that packs an effective 48 MP with a pixel size of 0.8 microns. The CMOS sensor features a Quad Bayer color filter array that bins adjacent 2x2 pixels to yield sensitivity equivalent to a 1.6 micron 12 MP sensor.
https://www.notebookcheck.net/Sony-s-new-IMX586-image-sensor-is-a-48-MP-stacked-Quad-Bayer-CMOS-chip.317756.0.html
So they should bin 6x6 pixels to get a good 1.3 MP sensor.
Then place an array of 7x4 such cameras on the phone and we would finally get close to a full frame! Cool.