Voice control: Do you have a strong accent? Unfortunately, the crap Android standard voice recognition has a number of problems, not least of which is using an internet connection if it's there, even if it's poor quality, this can lead to unacceptably high latency to recognize voice commands, even though then, at least, your language preferences apply to select the language model for recognition. Instead, I'm using the CMU Sphinx project's recognizer, but I have only standard english and spanish language models to use, so if you have a strong accent (Aussie or otherwise) it can interfere with recognition. I've heard from two people with French accents, one has no trouble, the other has a stronger accent and is not recognized.
On the tilt control -- I determine the baseline attitude of the device when start calling is switched ON, from there, a roll of about 10 degrees to the right will advance the call, roll about 10 degrees left will go back a maneuver. I won't read another tilt until you've gone back the other way at least 5 degrees. For example:
Start flat, screen facing up, click the start calling switch to switch it on.
Roll 11 degrees right -- Call advances and voice announces new maneuver.
Return to flat, the roll trigger will "rearm" as it crosses 6 degrees of tilt (11 - 5 = 6)
Roll 11 degrees right -- Call advances, etc.
Now, if you are real quick with the rolls and roll an extreme amount, you'll get this behavior:
Start flat, screen facing up, click the start calling switch to switch it on.
Roll 20 degrees right -- Call advances and voice announces new maneuver.
Return to about 11 degrees, the roll trigger will "rearm" as it crosses 15 degrees of tilt (20-5 = 15)
See the 11 degrees of tilt as > 10 degrees, roll trigger fires again, even though you didn't roll right again
I'm working on allowing you to adjust sensitivity... But if you know how it works, you can be careful and it will work.
Peter+