You should be able to upload multiple images when making a collage as long as you are signed into a Ribbet account (can be a free account or Premium account). If you are signed in you will see “Hi Username!” on the top right toolbar. If not you will need to sign in. Then when uploading images hold down the Command or Control key on your keyboard to select multiple files.
Let us know if you have any other questions or problems!
Regards – The Ribbet Team