Now Qt NFC detect only NDEF tags, signals targetDetected/targetLost are never fired for simple tags (extended description of issues: http://stackoverflow.com/questions/33346378/how-to-get-nfc-working-on-android-using-qt-5-6) because in QtNfc.java in start function it filters only ACTION_NDEF_DISCOVERED actions (and ACTION_TECH_DISCOVERED for NDEF tags that will report as tech) *without* simple ACTION_TAG_DISCOVERED.
But there are quite a lot scenarios when there is only uid of simple tags is needed.
So suggestion is to add another one IntentFilter for ACTION_TAG_DISCOVERED:
And change ACTION_NDEF_DISCOVERED filter to ACTION_TAG_DISCOVERED in setContext function.
Especially given the fact that getStartIntent already handles ACTION_TAG_DISCOVERED actions.