Someone knows a shorcut or a program to convert pdf files into rtf, wowrd or txt files with the Iphone?

Hi all,
as my Braille Display only accept files into txt, rot or word format, and I reeive verything in pdf format, I'm looking for a shorcut or an app which allows easily with the Iphone to convert a pdf file into txt, rtf or word file. Someone knows anyone, please?. Man thanks in advance. María