I'm currently leaning toward--
IxGyro
ixGyro - the true-attitude indicating glass cockpit app
Here is a list of phones they've tested it on (maybe an old list):
Google Nexus S (Samsung Nexus S i9023)
Samsung Galaxy Tab
Samsung Galaxy S2
Google/Samsung Galaxy Nexus
HTC Evo 3D
If I want to run it on my current phone I'll have to augment it with this device to provide the needed 3-d rotation rate sensors:
AHRS G mini
Some comments on the IxGyro website suggest that the Levil plug-in device will provide some advantage even with a newer/ higher-end smartphone that possesses 3-axis gyros as well as 3-axis linear accelerometers
Don't worry, I won't rely too much on it. Most of my blind flying is partial-panel and I'm pretty comfortable with that, I just want something that has some significant chance of giving me extra help if things get too loosey-goosey in extreme turbulence. I'll have freshly packed parachute also.
Any links to other appropriate forums where this is being discussed, would also be welcome.
S