I built an app with Drupal, and I would like to add step-by-step dialogs to help users learn how to use the app.
I found some boostrap plugins, but I would like to know if there is already a Drupal module that has this functionality.
The modules chrischarlton suggested were fine, but those are unsupported and not maintained.
I recommend using the Boostrap tour module. With this module, you can show popups step-by-step, attach the popups to HTML elements in each step, save the progress of the user, and let the user add feedback to the tour. However, you need to have a boostrap based theme in order to make it work.
Yes, there is.
Here's the relevant modules you'll want to review. Pick the one that fits your exact use case, and let us know how it works out for your site:
One other module that comes to mind is Tutorials (module) - https://drupal.org/project/tutorials - this one allows you to embed help videos, so it's different but you may find it useful on your site.
For the sake of completeness, there are a couple other JQuery integrated projects:
Also note that a Joyride-based tour is included in Drupal 8 core!