Android installers make sure that you have everything, so you can just download latest chapter and if you’re missing assets from previous chapters - it will tell you to download exact installers that contain your missing assets. In this case you will likely just need to dl installer 6. If you know that you’re missing several chapters you might not even need update installer, just download installer with larger number (6 currently) and usually it will be enough but if it’s not - it will tell you.