OpenFlashLight

Open Source Flash Light one button, stable and fast. (no ads of course).
https://github.com/tinmarino/OpenFlashLight

The important features are in AndroidManifest.xml :







And On :
cam = Camera.open();
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
cam.setParameters(p);
cam.startPreview();

Off :
cam.stopPreview();
cam.release();
cam = null;

Test if LED flash present in Android SmartPhone :
if (getPackageManager().hasSystemFeature(
PackageManager.FEATURE_CAMERA_FLASH))

Hope that helps.