Here's one that fits in your pocket and, with a little photography knowledge, your images will improve 200%!
Nova Off-camera Wireless Flash for iPhone https://www.amazon.com/dp/B00JNRW950/ref=cm_sw_r_awd_YkC6ub0T61R5S?t=imore-20&tag=hawk-future-20&ascsubtag=UUimUvbUpU2462791
Sent from my...