Too bad that there are no EXIF data in the files you posted. Might also have been good to post the original files in full size, so the extend of the problems becomes. Are the images crops? Or just resized?
I guess these are images in low light situations with high ISO rates?
Personally, I think it may not be a problem with your camera in particular, but maybe the camera just doesn’t perform much better?
I have also discovered that under low light the camera performance is rather poor. (as I have stated also here). I had some images with such noise patterns as well. Particularly towards the border of the image the quality deteriorates, which is not uncommon and can even be seen with DSLRs if you don’t use high end optics, so I think this also has to do with the lens quality. And of course, if the optic doesn’t let through enough light towards the border, the sensor will also struggle with the poor light that hits it.
Indeed, these kind of lines could also come from a badly soldered sensor, from a faulty sensor, but also from software issues.
Personally, I still haven’t yet discovered a mobile phone with a good camera, whereas Nokia usually was quite good with that (no experience with iphones), but still, it is just a phone camera. Tiny sensors, poor optics, bad software, no raw files output.
Not a good mix for photography. That’s why in past I have hardly used phone cameras. And I still think that the quality of the vast majority of phone devices is still not good enough.
It would be interesting though to see how the camera performs under sun light, or in other situations where you have plenty of light. I Haven’t had the chance yet to test it. Maybe in a couple of weeks …