write a simple code in on click or any action you want perform to share

String apk = "";
String uri = ("com.my.project");
try {
android.content.pm.PackageInfo pi = getPackageManager().getPackageInfo(uri, android.content.pm.PackageManager.GET_ACTIVITIES);
apk = pi.applicationInfo.publicSourceDir;
} catch (Exception e) {
showMessage(e.toString());
}
Intent iten = new Intent(Intent.ACTION_SEND);
iten.setType("*/*");
iten.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(new java.io.File(apk)));
startActivity(Intent.createChooser(iten, "APK"));