You can learn more about desktop testing tools through the various online resources. Quality assurance is essential for software developers as it allows them to ascertain everything is in order before they could either officially launch their commercial tools or before they could start making use of their tools for their specific needs.
You would ideally want to learn more about quality assurance online and perhaps seek to take any courses or training programs that could assist you to improve your knowledge about the various desktop testing tools so you can become proficient in testing your in house developments yourself.
Software developers need to be experts in quality assurance so things can proceed smoothly for them. However, since quality assurance is a specialist department in itself, you will find it necessary to specialize in it if you are interested in testing software programs from multiple sources.
There are several companies where you could outsource the quality assurance process to so you could free up some of your time to focus upon other stuff. You need to learn more about the various desktop testing tools to make it easier for you to take full part in the process of testing your software. Without testing your software before release, you would be risking its failure.