I use an ethernet-attached device to control my lights. It is a simple ArtNet/DMX controller in the form of a black(blue)-box (Enttec OpenDMX Ethernet - ODE) that is pre-wired and hidden away in my stagerack. There are many software-solutions to control ODE from computers or handheld devices.
My lights and effects (PARs, Moving-Heads, Haze, Smoke) are controlled by a free application for windows/linux/macos called Q Light Controller Plus (QLC+) running on a Macbook computer. There are shows/scenes/sequences set for every song.
Bandhelper is used to choose the right set of scenes for the song. It runs on a tablet connected to a M-audio USB/MIDI-interface that is passing messages to a Roland Audio/Midi-interface on the Mac. There are a few too many gizmos in play for my liking, but it works. The light-controller software can take input from the net using OSC and thus be controlled directly from the network using apps such as TouchOSC. It would have been nice if Bandhelper could send OSC-messages so I could get rid of the whole bundle of MIDI-interfaces and cables.
In addition to Bandhelper initiating sequences of scenes I have a bluetooth 4-button pedal that signals scene-changes to the software on my mac. Bandhelper chooses the song. A song usually starts with an introduction, and the pedal is used to activate the appropriate lighting for each section of the song thereafter (intro, verse, chorus, instrumental breaks etc). The whole setup gets rather complicated, but the ability to set a matching background for each song and place focus on the key performer(s) in the right places is a great addition to any stage performance.