Well I payed in total over 2 years 500+€ to doubleu for chips and playe for an hour a day, 4 days a week without ever winning jackpot, when looking into files hosted on dev20.doubleucasino.com from kali Linux Firefox dev tools. I indeed found a jackpot notification generator script where usernames are picked from a comment username wordlist stored on their server. So yeah definitely, jackpots are faked for giving players the motivation to pay in order to get that jackpot sometime. This made decision pretty easy to never give them a single penny again. I have send an email to both duc and Google and apart from receiving email from duc offering me refund to shut me up. I hope Google will come forth and delete the app from play store as for now they say their experts will investigate.

Likely so

Let us know and good luck.