If you'd like to use Luminair on multiple devices to control the same DMX universe at the same time, you'll need to use a DMX merger. Most Art-Net and sACN interfaces support some level of DMX merging, all with different capabilities. The Enttec ODE supports simple HTP (Highest takes precedence) merging from 2 sources by default.

Please note that your DMX interface may continue to merge signals even after one device has left the network. This can cause confusion if, for example, you make changes to the DMX universe on an iPhone, close Luminair, and then transmit DMX from another device like an iPad. The DMX interface may still continue to merge the levels last received from the iPhone along with the signal received from the iPad (or other device). On the Enttec ODE, you need to cycle power to the interface in order to release retained values from another device.

Also please make sure you are aware of licensing restrictions when using the app with multiple users on multiple devices.