I am trying to use stomp box to add chorus, but it adds a lot of static type noise. I am recording at 44.1 kHz. I saw another post that suggested that as a cause. Any other ideas? Thanks.

Welcome Merhere. 44kHz should be good, that's the default for most iOS apps. Is the app called StompBox by 4Pockets? Currently they have a note on their iTunes which states that it's not compatible with iOS 9. Are you running iOS 9? If not, does it work by itself, ie. standalone, or is the problem only when it's being hosted?