Currently SoM does not have an application especially for people who use their smart phones to be on the site.
As said above me, you can simply type the URL in the phone's internet and get to the site, or you can choose to use the online phone version of SoM which is made especially for members who usually get online by using their phones and wish to enjoy the site and feel comfortable.
If you find this as an important feature that has to be added to the site, please comment on this thread which was opened especially for us, the members, to suggest different features and possible updates we would like to have on SoM. If your idea is actually good and acceptable, you might see it being developed here!
So here is the thread:
Also, the administrator ( Petrarca ) said in a thread that SoM is going through big and important changes and updates.
So you can wait for good !