The Android Debug Bridge (adb) is a powerful tool that allows you to communicate with a connected device. One of my favorite features is the ability to start an Activity , BroadcastReceivers or Service while passing intent parameters to it, all from command line.
e.g starting an activity takes the form:

adb shell am start  -n “[your package name here]/[your activity path here]”

Take a look at the attached gist to see how you can do this.

[1] https://gist.github.com/ckurtm/ea4ba85c1dfc7be4a43b
[2] http://developer.android.com/tools/help/shell.html

Marking your Activities,Services and Receivers as exported in your app manifest might not be something you want to do in a production app as it might be a security risk if you do not wish to share you app info with any other app.