If anyone is still wondering how to do this, you first download the .apk file as usual. After it has finished downloading, download Documents by Readdle from the app store. Open it, and once you get to the main screen, click on the + button at the bottom right corner, and then choose “Add from iOS files”. Go to the directory where you have the .apk file saved, and click on the .apk file. Now, rename the .apk file and replace the “.apk” string at the end of the file name to “.zip”. After that, just click on the .zip file you renamed, and soon after you should see a new folder. Open that folder, go to assets, and then click on the file called “index” or “index.html”.