What collage app will create a picture collage with no border around photos?

I am looking for a photo collage builder app which makes collages that have no border around them. I see collages that have the white border surrounding each photo but I want the photos just to blend together without having any borders or anything in between each of the photos I choose.

The app "p!coverlay" is shown in the screenshots below. You can enlarge or shrink each of your photos to any size you wish, and you can also overlap the photos on top of each other. This app also allows you to position them one by one so that there is no space between the photos if that is what you wish to do.