My paid Android app (.apk) size is 36 Mb but when downloaded from Google Play it is increased to 95 Mb in the phone !
I can see that the encrypted app file stored in data/app-asec is 70 Mb.
I use a single APK file which is created using the Export feature in Eclipse (Which handles signing and alignment). The 36 Mb is mostly graphics (.png).
I have added these settings to the manifest file:
android:installLocation="preferExternal" (<manifest>)
android:allowBackup="false" (<application>)
I have included a PDF library (Approx. 10 MB).
When debugging my app using ADB the size in the phone is not increased (Still 36 Mb).