I didn't see a comment section, so I started a topic; sorry if this wasn't appropriate.

I downloaded the apk onto my device, but I try to install it, it gives me an error message. "App not installed." I know it's not a storage issue. Is there something I can do to install it?

Unfortunately, Android apk is not my field of expertise.  Your problems can range from a number of variables, including having a phone that is either too next generation for renpy to work properly, or isn't up to date to be compatible with renpy.  You can try using free to download APK installing apps from Google that "may" solve your problem with installation.  

P.S.  I suffer from similar issues everytime I try to update Sins on my on cellphone, and know it works only thanks to Blue Stacks on my CPU   x3