Very good app, does the job
A few suggestions:
* sometimes you have to improvise, for example if you want to understand freeT you’ll need to convert from nmol to pmol for yourself
* it could use a Universal option where you choose what units you want (eg ng/dL to pmol). You could even save this as a new option in the list, and name them
* the ability to pin 8 favourite conversions you use in the main list - and have these appear at the top
* it needs a better icon - something clearer than purple on purple
Overall a good job - recommended!