hi, if you didnt know, the android version is not on the play store, it is an apk that you download to install. this is beacuse the game uses assets from deltarune and undertale which the play store does not allow. the same goes for iphone (ios) appstore, however ios does not have an apk eaquivelent (but might in the future), for now making apps and games for the iphone without the appstore is not possible. hope this was helpful!
also the fire tablet runs android i think so just look up a tutorial on how to install apks on a fire tablet \__/( ' . ' )\__/ idk