The TabletStage from Mighty Dwarf has a split personality... and that's a good thing! Aside from splitting apart to form an easel for iPad, iPad mini, or other tablets, it also includes stereo speakers and can accept audio via Bluetooth, NFC (with supported tablets), or 3.5mm audio jack (cable included.) It charges via Micro USB (cable included) and, at least for my review unit, ships pre-charged and ready to use!
The TabletStage folds into a compact form for easy stowage in your gadget bag. When you unfold it, the device forms a full-size "stage" for your tablet. The audio quality is surprisingly strong, thanks to a pair of clever slits in the base that act as a subwoofer. If you cover them up, you'll hear the difference.
Since I used a prerelease version, Mighty Dwarf may already have addressed my one concern: the device shows up as Bluetooth when pairing instead of something more descriptive. Since it's universal, it will work with just about anything, making it future proof!