I am not sure how can you do it concerning already released games, at least if you buy and read them in an android. But you can try it with the different WIP in this forum. When you open one of those games, they open in a different browser window, right?
Ok, you take the link of the game (fake example: https://dashingdon.com/play/author/wip/mygame/index.php?cb=11111), delete the last part of the location and write “scenes” in its place (so that you might end up with something like this: https://dashingdon.com/play/author/wip/mygame/scenes/).
And you will get access to the directory of the files that are part of the game, if you open them you can see the code. Most authors don’t mind you doing that, but unless you are doing to provide better feedback on the beta test (it’s easier than to actually play the different paths in an infinite amount of playthroughs).
There is a thread discussing it in more detail (and I think they address the problem of how to see already released games’ code), here goes the link: How to see other games’ code
(Edit: Oh, @Jacic beat me to it, but I am still leaving my reply up, as something like a very condensed version of how that can be done regarding WIP, just in case you are as lazy as I am 
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