This is a major problem that i have meet and took me some hours to find the answer, because no one wrote a clear solution, even though is a very simple one.
If your Android virtual keyboard overlaps your editText that is on a lower part of the screen, then you need to modify your AndroidManifest file.
How? Very simple in your activity you need to add:
android:windowSoftInputMode="adjustPan"
More clearly.
Your declaration of activity looks like this:
<activity android:name=".Main" android:windowSoftInputMode="adjustPan" </activity>
I hope this helped you.