The reason for installing modules and plugins in Joomla is to expand the functionality of your website. The following is a list of esential extensions we have tested on our templates for compatibility. We fully recommend the use of these extensions. You can find thousands of other extensions here.
While these free Joomla components and modules are not perfect, we have found them to be highly notable Joomla additions. JoomSpirit has no affiliation with any of these extensions or their developers.
Note : JoomSpirit does not provide support for these extensions. For product support, contact the developer associated with the extension.
1. Qwant Maps : opensource and privacy preserving map module (non-commercial) by Dimitry Zhuk
free and collaborative geographical database
2. A very good wysiwyg editor : JCE non-commercial
An award-winning, configurable WYSIWYG editor for Joomla.
Includes advanced Image/Media, File and Link handling, plugin support, and an Administration interface for editor configuration.
3. Sigplus Image Gallery non-commercial
Sigplus Image Gallery is a straightforward way to add image or photo galleries to a Joomla article with a simple syntax. It takes a matter of minutes to set up a gallery but those who are looking for a powerful gallery solution will not be disappointed either : sigplus is suitable for both beginner and advanced users.
Despite its versatility, sigplus is completely free.
Tips : If you have this error : NoDecodeDelegateForThisImageFormat `/tmp/magick-XXbYDDua'
Edit the Sigplus plugin and change the image library from default to Graphics Draw.
4. JPEG Optimizer non-commercial
Not a Joomla extension, yet very useful software. JPEG-Optimizer is a free online tool for resizing and compressing your digital photos and images. No software downloads are required.
5. JSitemap professional extension commercial 
Boost your indexing with JSitemap, the advanced sitemaps generator and SEO indexing tool for Joomla!
One of the best extension i use in all my joomla.
I recommend for the support.
6.Add Schema Structured Markup for Better Joomla SEO with Google Structured Data
Get the best structured markup extension for Joomla
... you search another extension non-commercial
The Joomla extensions website contains a list of more 8000 extensions. It's a good place to find your happiness.
