I'm not sure about dedicated aviation apps for the Android.
I'm using OziExplorer Android on my Nexus 7. It seems to work very well with maps/charts that I scanned myself.
I'm currently using the GPS receiver in the Nexus 7 and it seems to be very well.
A few minutes ago I managed to connect the XGPS150 to the Nexus 7 via Bluetooth without any problem.
I decided to keep my iPad Mini for now, although I won't be using it for navigation since OziExplorer won't work with the iPad OS and mine doesn't have the built-in GPS. The Mini has a slightly larger screen than the Nexus 7 so I like it better for photos and videos. Also, my iTunes music syncs with the iPad but, of course, not with the Android.
My my purposes (strictly VFR in a relatively small area and remote enough that I can't get XM Wx, radar or cell-phone data), OziExplorer made the most sense. I have VNC's (Sectionals) of my area, and also more-detailed 250k and 50k topo maps on the Nexus, so it's also useful outside the airplane for hunting or canoeing.
More details on the OziExplorer web-site. You'll need the PC version ($109) in order to scan and calibrate (geo-reference) your maps. A license for your Android device is $25. The program is still in Beta, with future versions free as long as you buy the licence. There is, of course, no annual fee since you'll be the one responsible to up-date your charts as necessary. Out here in the boonies there is little or no change from year to year.
If you have digital charts available you won't have to scan your own, though you may have to geo-reference them - a simple process.