SMARTFONES are based on the positions of the cEEGrid electrodes, i.e. they are not built on the standard 10-20 system. All the electrodes are located in the area around the ear. This is why they are perfect for auditory studies, since the electrodes cover the auditory area and the central electrodes, which are used in these kind of studies. Here are a few links where the cEEGrid results were compared to the full 10-20 montage.
And here is the example for what they have been used so far in the scientific research, and shortlist of what can be measured with the cEEGrid:
The same principle is applicable to SMARTFONES.
See the layout below: