Where are binaries installed?
Android apps aren't binaries.  They're .apk's, similar to Java .jar files, and .dex or .odex files when in bytecode form.  They're run in the Dalvik virtual machine, again very similar to a Java VM.

You can launch an app from a shell as follows:

am start -a android.intent.action.MAIN -n &lt;package name&gt;/&lt;activity name&gt;


For example, Angry Birds:

am start -a android.intent.action.MAIN -n com.rovio.angrybirds/com.rovio.ka3d.app


The name of the activity is found in the AndroidManifest.xml file inside the .apk under //manifest/application/activity/@name.  For Google Voice there are quite a few activities, and you may need to use other intents.  I don't have SL4A.

You can also disable apps temporarily with this:

pm disable &lt;package name&gt;


And re-enable:

pm enable &lt;package name&gt;