mobile wordpress themes give a lot of features which are essential for any mobile user. The layout is simple and mobile friendly. The navigation is improvised to be best viewed in a mobile. Here you could have two options, first is you have a responsive wordpress template which could fit in all the devices the user is viewing your site on or second you could go for a dedicated wordpress theme for mobiles on a subdomain m.yourdomain.com This would help you to target your mobile users in a much more specific manner and get the best out of them.