I use Tomdroid, a Tomboy client for Android. I use it mostly for local notes, although it does offer some sync options. I think it's still in beta.
https://play.google.com/store/apps/d...d=org.tomdroid
Since my tablets aren't always on a network I also have (and use) Maps With Me -- the free version -- with map data downloaded for several northeastern states. It's a good off-line map, but doesn't give traffic data, of course.
https://play.google.com/store/apps/d...ithme.maps.pro
I also have Dropbox to exchange files with my computers.