iOS oscilloscope app

I purchased this iOS oscilloscope app yesterday and am having trouble getting it to work with line in to my iPhone X

Oscilloscope by ONYX Apps https://itunes.apple.com/us/app/oscilloscope/id388636804?mt=8

I’m trying to view the wave form generated by 0-coast and have tried running the audio through Dude mixer and straight from 0-coast to my iPhone X using both stereo and mono 3.5 mm cables and the 3.5 to lightening adapter that came with the phone.

Wave froms from the phone mic look great. Wave froms from line in is only just barely wobbly and could be caused by ambient room noise that’s getting into the mic.

This link is in the app settings page but not visible on the iTunes Store. I don’t want to spend much money on additional things to get this working, so best bet and cheapest options would be great to hear.

http://oa.onyx3.com/signals.html