I created a new Sencha Touch 2.x application, and created a Tab Panel. I attempted to set the tabBarPosition to bottom, but I can't seem to find that option in the configuration window. When I search for it, nothing appears. Should the Tab Panel configuration match the documentation at http://docs.sencha.com/touch/2-0/#!/api/Ext.tab.Panel ?
This is a little bit of an odd situation. The Touch API defines not one but two ways to control the position of the tab bar: (1) the 'docked' property of the tabBar sub-component-config, and (2) the tabBarPosition config on the tab panel. Internally the Touch framework code maps 1 to 2, and it's up to the developer to choose the method they prefer.
Within Designer, we've chosen to expose control only via method 1; you select the tab bar component and then set its "Dock in parent"/"docked" property to control its position. We feel that this provides a more consistent user experience because it matches how you set the position of other Toolbar components. By only exposing one method we avoid potentially confusing situations when both are set differently. That said, we're certainly open to further discussion on the issue.