Ram & CPU alert when testing Android and IOS application

My Android and IOS application recently has performance issue on production, where it consumes high amount of RAM on devices with low RAM (~ 1 - 2 GB).

I would like to add a non-functional requirement for development team that the app should never use RAM more than, says, 500MB. And I want to add this to acceptance test criteria and would like to know if there are some existing practices or tools people is using for this kind of test.

My early idea is to install another monitoring app in QA devices that can track RAM usage of the target app and setup an alert threshold, but I cannot find such kind of app in Play Store/App Store.