Chroma Collage can be used to create montages and collages of your favourite images.
Just take your photos against a plain, bright green background so that they can be used within the app. Green paper is ideal
As long as the green is bright and well lit, it will be automatically removed when importing into Chroma Collage.
You can also use clipart pictures on a green background or png images with a transparent background
Once you have your photos, import a background and then import your green screen photos. Play with the layout and position of the photos, resizing and rotating them. You can also copy and paste images once they are in the app.
You can use the eraser tool to clean up the imported images.
When you are ready, save the collage to your photos.