I'm looking for a way to give style to my app tabs Android 4 similar to the image and that each tab has its own activity class.
As a note, a TabHost is a native Android piece, so it will be rendered differently per phone (unless you create the tab images).
ActionBarSherlock's bar will provide an ICS style navbar experience to pre-4.0 devices in a more dynamic manner: http://actionbarsherlock.com/. It is also a very nice library for other actionbar related items if you want to support earlier targets.
Once you have the tab bars in, per-tab fragments are probably the easiest way to go: http://thepseudocoder.wordpress.com/2011/10/13/android-tabs-viewpager-swipe-able-tabs-ftw/