I do gigapixels also. I don't see reasons (except participating in dull gigapixel rush:) to do it with more than 400mm + FF (Nikon D800e would be perfect). Adding more FL (especially with...
now my phone also sees it, (after 2 hours after this post).
I want to install it on my phone, not on a computer, so I use Google play store - there is no such application there (at least now:)
Interesting, Google Play finds nothing on Snapseed :)
google+ ?! what is it?