1) How to set a publishing target for mobile device only in Sitecore?
2) How to view a web page made for Device view without providing the query string (sc_device=mobile) for user use?
Just to update the answer from the comments:
Out of the box Sitecore is not able to detect mobile devices vs pads vs desktop. The easiest way to do it is to turn on device detection in Sitecore (https://doc.sitecore.net/sitecore_experience_platform/82/developing/device_detection/device_detection/set_up_device_detection). Then Sitecore will do all the work.
Or you can roll you own. https://briancaos.wordpress.com/2012/04/12/identifying-mobile-devices-in-sitecore/