Phone number based Devise authentication for mobile apps

[vlad]

Hi, I am looking for something similar to Confirmable module, but for mobile phone numbers--basically accepting phone numbers as primary ID instead of emails, and then confirm the phone number by sending an auth code as SMS message to the user's number via something like Twilio, and then let the user confirm it by entering the code (or even let the user click through a generated link to verify just like they do with emails)

The reason I ask is because nowadays I see that feature in almost every mobile social apps. There's gotta be someone who thought this was a problem and created a module for this. However I couldn't find any useful ones. Actually to be precise, here are the only three relevant links I've found on this:

    https://github.com/giano/devise_sms_activable
    https://github.com/baranov-sv/devise_sms_confirmable
    Rails register User using phone number and confirmation

None of them leads to a working solution (I've tried devise_sms_activable but it doesn't work for rails 4, plus I'm wary of the low number of stars) So I wanted to ask if there's any viable solution to this. Am I missing something? Has this topic been brought up among the Devise developer community?

I would love some help.
Even if there is no existing solution for this, could someone explain why this is a hard problem or why there is no module like this?

[Kevin McCaughey]

You could do what I did and add an authentication for mobiles as an additional step (i.e. I want to make sure they used the right phone). I didn't need to do much to devise for this, except take account of updating the phone number when it changes. I use Plivo for the SMS part and handle the SMS's myself. It's pretty simple.

[Mark Quezada]

I just started looking into the same thing, for the same reasons. Did you ever settle on a solution?

I've looked through various two factor auth solutions, but this is different since there really is no password, only one-time passwords. The "WhatsApp" app does exactly this and I'm interested in mimicking that user sign up flow for a social application.

-m