Not sure if this helps but searching the google play store there is an app called PLC-5 Mobile HMI. It claims it can connect to an Allen Bradley PLC-5/40e unit. There is a free and paid for version. The free version can connect to the status registers while the paid version can also connect to the input/output data files. https://play.google.com/store/apps/details?id=com.jca.plc5exp&h l=en It claims no opc server or third party libraries so I assume using the ENET protocol.