Watch App fails to work properly

Money wasted. App bought for using with Watch but it "forgets" very often to notify about completed session. After some time when I check the time and wake Watch+Focus app - THEN it shows that session is completed. Too late. Thats for 5€ app? splendid... I wish I couldnt refund.
And why there is no option to choose what to see at Watch glance? The remaining session time is more important than number of completed sessions. Come on.

domikPL about Focus - Timer for Productivity, v1.1.2