We have an assortment of templates that allow you to put captions on each photo so that you can have different text for each slide. These templates are under the Slideshows category in the Ripl template catalog. To reach the template catalog, you can select a post from the Home screen or start a new post from the "+" button. You can then access the templates catalog by tapping the More Templates box on the Customize step.
In the desktop version of the Ripl app, once you add more than one photo to a slideshow template, arrows will appear under your post's preview, which will allow you to switch between slides. You can add more images by clicking on Media on the left side of the screen. You can add text for each of your slides by clicking on the Text option.
This blog post also walks you through the different types of templates available in the Ripl app.