I did not notice any change on my phone temperature...the app are working permanently (once you start, it is active 24 hours).

It is not a lightning withdrawal...you can withdraw to Ember app's BTC wallet, and from there you can send it anywhere (onchain or lightning address).

But...your doubt about payment is real, I agree. I think I will remain to "verify" if it is for real, or fake...I have nothing to lose, just 2-3 minutes daily :)