If you want a true alternative to Android, there are a few. I am sorry to say, free software fans, the best and most functional alternative to Android is still iOS. Most people looking for Android alternatives are not, however, looking to switch to an Apple device. There are a couple of Linux-based phone systems out there, most notably SailfishOS, which can run Android apps (I will be testing this next), but in my testing, none of the Linux-based operating systems are ready to be your everyday device.