Easy Images is a joomla! 3 plugin that handles the images a user includes in the articles.
There are two options:
Handle the images individually or group them in galleries.
Handling the images individially means that each image will be displayed in it's own modal view when the visitor clicks on the image.
Whereas grouping them in galleries, upon loading the page the images will be grouped into galleries and placed at the bottom of the article.
Whenever a visitor clicks on an image (of a gallery), the whole gallery will be displayed in a modal view with buttons to navigate to the next or previous picture of the gallery.