In most other languages there are things called exceptions that can be checked for.
In some languages, exceptions can be checked for globally so that if the program crashes anywhere, it breaks out of what it's doing and the programmer can decide how to handle the crash, like a bug report. In JS there is the try/catch which can be used on blocks of code to find when things go wrong.
In Construct there appears to be nothing like this. In most languages
would cause an exception. In construct, it let's it fly and gives the results as Infinity. This tells me that Construct is likely set up to at least avert crashes caused by the programmers bad code.
So, as far as I know, there's no way to have your actual app check itself for errors or crashes and report those crashes back to you. My method of debugging is to run in Chrome and hit the F12 to bring up the developer console. I keep watch on it to see if any serious errors are occurring. If my app runs on my hardware, it's able to do everything I want it to do and I see no errors, then I've done all I can.
As Ashley pointed out, there are so many different hardware and software configurations out there that it's impossible to test for all of them.
About the closest thing I've found that can help you track down errors is this:
I haven't tried this, but supposedly this JS will capture the console log (in Chrome, I don't know about other browsers). You could likely adapt this to store the log locally and send that log back to a web server somewhere where you could review it. Determining whether the app crashed or not is another ball of wax you'd have to solve. Another thing that could give you some insight is the PlatformInfo plugin. The information it provides is pretty limited but you could also have that sent back to a server to at least know what OS the user is running.