sync rtf files from mac to iphone

I was wondering the best way to keep file up to date between my iphone and mac. I will take notes on the job and when I get home I will edit them on my mac and may add to the note form my phone the next day. I have tried a few of the apps like notability and plain text, but nothing seem to work well together with drop box. I have tried box put do not care for the format. I am willing to try different thing if they work together. 😕