I believe that the use of the mobile phone to carry out instant transactions would not help too much the massive adoption of cryptocurrencies, because the vast majority of people use the mobile for communication and entertainment purposes, not to carry out their financial transactions. In fact, there are already banking applications capable of doing this, and yet its use is not widespread.
But perhaps the acceptance of the banks to carry out transactions with cryptocurrencies could be more useful in that sense, as well as the use of simple platforms to make minority purchases in neighborhood stores and department stores.