user3029: Which coins have the ability to offer a 2 factor authentication feature where it requires a secondary approval mechanism in order to spend from an address? 

user37625: Have a look at byteball (http://byteball.org). It supports n-of-m wallets out of the box which can be used to implement a basic 2FA mechanism (2-of-2 with your desktop and your smartphone, for example.)
It also has a chat mechanism built in, which can be used to communicate between the devices and which would probably enable you to do what you intend.
There are a number of other interesting features listed at the web site.

3029: <p>Which coins have the ability to offer a 2 factor authentication feature where it requires a secondary approval mechanism in order to spend from an address? </p>
 37625: <p>Have a look at byteball (<a href="http://byteball.org" rel="nofollow noreferrer">http://byteball.org</a>). It supports n-of-m wallets out of the box which can be used to implement a basic 2FA mechanism (2-of-2 with your desktop and your smartphone, for example.)</p>

<p>It also has a chat mechanism built in, which can be used to communicate between the devices and which would probably enable you to do what you intend.</p>

<p>There are a number of other interesting features listed at the web site.</p>
