Reported by Netherlands MDD Researcher:
The passive app seems to drain the smartphone battery very quicky. For instance, I completely charged my smartphone and after 3 hours without using it, the battery level was 64%.
Interestingly the Moto G5 and samsung A5 have comparable battery tests results so maybe there is more going on here https://www.gsmarena.com/battery-test.php3?idPhone=6761#show
I'll add further details when received.