Had no idea about this. I liked Google's Auth since it was simple but it missed the crucial backup feature. Authy is nice but you're putting trust in a 3rd party that doesn't have a channel for donations, though it seems they're making money through SMS (Twilio).

andOTP is just what I was looking for since it's FOSS and had backup! This would have been a lifesaver when I lost my phone but glad to have run into it now.