What a great topic! Thank you for posting, Cassie!
The list is looking very good already!
I will add to the cellphone and vet number that I had a page of several numbers taped to the top of my foaling kit with numbers to THREE vets and a few others who I knew I could call if i needed advice fast. I wanted many options in case of an emergency and I didn't get an answer the first call.
a flashlight or two.
I also had a small, thin wooden rod cut at an angle at one end to use as a safer way to rip the bag then using scissors. You could also use a tongue depressor or popsicle stick cut to an angle and it would work the same. I did have to use this too because my filly's sac was so thick I couldn't rip it with my bare hands/fingernails.
I used a TON of towels too so be sure to have a nice clean pile of them- not just one or two.