I actually have a custom util that I put together that runs on my PC and provides a web interface (as well as desktop control) I enter the universe number and channel numbers for each element, which are loaded into a list. I can then go out front with the ipad, and turn on individual elements (or groups) to make sure they're working properly, including choice of colours etc. Saves me running upstairs and back down to do my testing. Also saves me turning on all lights when setting up each item.
I really don't have the time to try and package it up for generic use, but any programmers out there that might want to have a play, I'm more than happy to provide the vb.net source code.
It'd actually be very simple for LSP to offer the same sort of functionality as this - allowing people to test their displays via a web browser - might suggest as a feature for the new version.
Another route you can go is to install SACNVIEW on your PC. It can run sinewaves and other test signals and contains a DMX channel monitoring function so you can troubleshoot when/if needed. Being able to "watch" LOR/xlights/SACNVIEW signals has helped me in the last week or so in isolating to "just" LOR for example.