Lovely! I made a spring collage today too, just using Photoshop... I wonder what your app is?The kowhai right outside my bedroom window isn't flowering yet, though it won't be long - the buds are yellow.
The App was a free one for Mac called CollageIt. I've got a large kowhai tree in my backyard that isn't in flower yet- it always seems to be 'later' than many others. Not sure why, as it is in a sunny enough spot. It was the collage on your site that inspired me to work out how to do one!!!
Is that a dogwood in the centre of the collage?
Ummmm does dogwood mean toilet? Yep, there is one of those behind the cherry blossom....