Iphone photo frame/collage app without white borders?

I'd like to DL an app that lets you make collages but without the border in between the photos.

I have no idea about iPhone app which can make college without borders
but I know many good online photo editor which do this work
such as picmonkey
Fotor
their collage is very easy to do
for example
open the Fotor:http://www.fotor.com/
choose photo stitching, and then drag each photo into your collage editing space
you can adjust the border color and size
if you don't need the white border, just adjust the border size to zero
Wish we can have cooperation