We recently added Android fingerprint authentication to our app. Currently, only 51% of users who have seen the fingerprint prompt have enabled the feature. I'm not sure if the number is low due to the design/method used for the prompt. Does anyone know what percent of fingerprint phone users generally enable fingerprint for app authentication?
I find this very interesting, since your number are in correlation with those mentionned in those studies (by Gigya and Paypal, so it's quite relevant) :
So your number is not very low, it's completely average. That's it for the raw information. Personnally I would not use it, but the two studies proves that 50% of the users are ok with it.
If you want the user to use the feature, give it more affordance, make it more visible. Usually those functionalities are lost in an abyss of menus, and given the fact that users don't like to dig deep into settings, they don't even know that it exists.
Edit : to answer your comment, here is two additionnal studies, one comparing ios and android in many points, the second has been conducted with 20 iphones and 20 other phones.
These are general results of course. But I see the problem behind your comment, and you won't find a study that will explain your special case. These studies provide an overview of how users tend to behave with fingerprint authentication. In order to know why there is a gap of 33% you must study your user, and don't forget that android users and ios users are usually not the same at all. Apple devices are usually more expensive and bought by technophile who love these kind of gadget (fingerprint, Siri, etc.). Expensive Android phones exist too, but Android is the main exploitation system for most middle-range smartphones, and those people usually care less about these kind of things. The first study provide very interesting results about that. If you want to understand precisely the reason why your feature doesn't meet success on one platform, you have to conduct your very own study to clearly figure this out.