ThumbCal Question

[Acedooncoon]

I would like to start off by saying..Im sure that this question has probably come up before...But I cant find it on here so I thought I'd ask anyways...So here goes...

Is there anyway that I can replace my current calendar with the app. "Thubmbcal"..I actually like that one a better..I just came across it a few days ago but cant figure out how to set it as my "default" calendar..If anyone can help me with that it will be great. Thanks a bunch...