How can i set this theme visible only for mobile devices?
Default installation instruction allows to make the theme visible only for mobile devices. Please navigate to Admin -> System -> Configuration -> 'Design' tab -> Themes' Group and add exception m001 to your theme value set at 'Default'. Then please add next Matched Expression in order to detect mobile devices
iPhone|iPod|BlackBerry|Palm|Googlebot-Mobile|Mobile|mobile|mobi|Windows Mobile|Safari Mobile|Android|Opera Mini
In case you want to use your default template on such devices like iPad, then the next exception string can be used:
(iPhone|iPod|BlackBerry|Palm|Googlebot-Mobile|Mobile|mobile|mobi|Windows Mobile|Safari Mobile|Android|Opera Mini)|(!iPad)