Hi.
Perplexed and annoyed me for a while, then it occurred to me that the number was incrementing by one per day and was always equal to the day of the month! Go figure.
Turn it off, or into something more useful (e.g. Number of events and tasks today) via setting --> preferences --> badge type.
I've been quite pleased with this app until today when I've started getting intermittent meaningless (to me at least) pop up exception messages. Hopefully it happens again so I can properly note the exception and alert the developer.
Happy trails.
Nigel.