Grimrock

I just downloaded grimrock on my iPhone 6s. I am using latest iOS. I get complete silence. The game works but there's no sound whatsoever. I tried adjusting the volumes in game, in iOS, using headphones etc. but still I get complete silence.

Is there a workaround for this bug or any other thing I could do to get sound in Grimrock on my iPhone 6s?

I can actually confirm that for iPhone 7 and latest iOS as well. I hadn't noticed because I always turn the volume off (because I sometimes play at work). Will see if I can grab an admin to come take a look at this thread.