Questions on using the day minder feature on alarm~reminder app

Hello, how many of you use the day minder feature on the alarmed ap by Yoctoville??
I have a trouble hearing sound alerts when I set up day minders. The user guide says I can use an option to turn off the message alert and hear the sound only, but this feature doesn't seem to work for me at all.
Any tips for solutions?
I cannot find a way to contact the developer of this ap either.
Any suggestions on how I can contact?