I started my hike with a used iphone 4. The camera was terrible, the battery life was terrible, it couldn't run Guthook well. It was like carrying a small rock.
I got a Moto X 2, which has an excellent camera, good battery life, and otherwise suits my needs. I signed up for month to month Verizon at $45 exactly for 1Gb of data, which was more than sufficient for my hike. I texted a lot of pictures to family to update them where I was, and involve them in my hike. I didn't download videos are do a whole lot of web surfing.