Originally Posted by
GUWonder
Is there any ability to use MPC without use of the MPC app versions released by this app’s maker/provider?
Don't know. I've had NEXUS forever so it doesn't really apply to me. I think you can just walk up to the machines (APC?) and US/CAN citizens and ESTA users can use them without having used the app.
Edit: Yes:
https://www.cbp.gov/travel/us-citizens/apc