7. The portable device of claim 6 , further including instructions: to simulate shifting of the application display region in a first direction upon detecting user selection of the prior context region; and to simulate shifting of the application display region in a second direction, opposite the first direction, upon detecting user selection of the link region.
6. A portable electronic device, comprising: a display; memory; a music player application stored in the memory; one or more processors; and one or more modules stored in the memory and configured for execution by the one or more processors, the one or more modules comprising instructions for: displaying a current application context of the music player application in an application display region of the display; displaying a navigation bar adjacent to the application display region, the navigation bar including at least three horizontally adjacent regions, comprising a current context region for displaying an indicator of a second application context comprising the current application context, a prior context region for displaying an indicator of a first application context comprising an application context preceding the second application context, and a link region for displaying an indicator of a third application context, wherein: the current context region, the prior context region, and the link region each maintain a fixed location on the display in the navigation bar, and the third application context includes a player that controls a song playing in the music player application; shifting operation of the portable device, upon user selection of the prior context region, to the first application context, including instructions to display in the prior context region of the navigation bar an indicator of a fourth application context comprising an application context of the music player application that preceded the first application context; and shifting operation of the portable device, upon detecting user selection of the link region, to the third application context, including instructions to display in the prior context region of the navigation bar an indicator of the second application context.