andy I have ultegra Di2 I never updated it am I missing out on anything as it seam to work flawless any news on the android app they where supposed to be releasing, and what is syncro shift
Shimano, keep updating the firmware to improve functionality and add new features, although I have never experienced a better performance once I update, it has always worked flawlessly. The new features like being able to use XT/XTR derailleur combo with 6870 Di2 hydro shifters is a new update a few weeks ago, my new bike has this setup. Syncro-shift is, I believe a one finger function where the front and rear derailleur will simultaneously changed to move you onto the next appropriate ratio, so if you cross chain big/big the next change will alter both front and rear to next nearest ratio.
The other function which has been out since Di2 became available is multi-shift, where you hold the button and the rear derailleur will travel the cass rapidly
Here is the news re Phone firmware updates
http://bike.shimano.com/content/sac...mano-advances-wireless-di2-functionality.html
You will need the new bluetooth battery to make it work, I got this on my new build but still choose to plug in my PC and use the SM-PCE1 to update and configure the shifters.
Edit Ive just updated my bikes, the road Di2 6870 updated, I couldn't see anything to do with syncroshift. My MTB/Road Di2 updated the BT battery and then I had option to choose ratios in a setup table. It asked for front chain ring and rear cassette ranges and then listed the overlap ratios. No mention of synro-shift again, I'll go for a ride shortly. So it looks like on first impressions that the battery is the item and needs to be BT version. I'll do some more investigating.
Edit 2 No syncro shift on either bike, I think I need the XT/XTR bluetooth thumbshift adding to my combo bike. Cant be bothered with that at present, hopefully more updates in the future
. When we're in Wales sharing a room and you're sleep talking about riding around watopia, I promise I won't put a pillow over your head 
goodbye my friend.... and good luck 
