The Cisco_Proc_App model associated with the Cisco APIC model does contain memory attributes that can be used for memory.
Using the directions outlined in knowledge document
KB000048408, set the following attribute on the Cisco APIC model to the associated values:
NRM_MemoryModelTypeToRead - 0x21006e (This is the model type handle of the Cisco_Proc_App model)
NRM_MemoryFreeAttr - 0x212b42 (This is the cpmCPUMemoryFree attribute on the associated Cisco_Proc_App model)
NRM_MemoryUsedAttr - 0x212b41 (This is the cpmCPUMemoryUsed attribute on the associated Cisco_Proc_App model)
NRM_MemoryUtilAttr - 0x0
NRM_MemoryUtilNameAttr - 0x0
NRM_MemoryTotalAttr - 0x0
After setting the values for the above attributes, right mouse click on the device model and select Reconfiguration -> Reconfigure Model from the menu.