Widgetkit
Widgetkit by Yootheme is the best slideshow program for Joomla that I have used. It’s easy to use and has almost every slideshow feaure you can think of.
And if that’s not enough, it can easily create galleries, tabs, sliders, HTML5 Video with legacy fallback, and more.
Widget Kit widgets are also responsive. They scale to fit the device: laptop, desktop, phone, tablet.
This extension costs around $37, but it’s worth every penny. And you can get a Joomla or a WordPress version!
YooTheme Warp FrameWork and Templates
YooTheme Warp FrameWork and Templates are one of the best Joomla template systems I’ve tried. Their designs are clean and modern and they are now adding responsive designs.
One of my favorite feartures of the Yootheme templates is the number of module positions: every template comes with over 15 module positions, many of which adjust the module width automatically depending on how many modules you add to each postion. As a result, without writing a line of code, you can configure the templates for any layout, from very simple to very complex.
If you do need to modify the template, you can easily create your own style. Using your own styles prevents your changes from getting overwritten by a template or framework update.
And finally, like WidgetKit, you can use Warp templates in Joomla or WordPress. Learn one framework for both platforms.
K2 Content Creation
K2 is an alternative to the default Joomla article creation component. With K2, you can easily add comments, author info, slideshows, images, file downloads, extra fields, link, related articles and more to the default article editor screen. Furthermore, you can create different templates for different types of articles.
If you find you need fields than those provided by the default Joomla article component, check out K2.
Zoo by Yootheme
Zoo is similar to K2 with a couple big differences. First, Zoo costs $128. Second, Zoo comes with 8 pre-built apps: Blog, Product Catalog, Cook Book, Movie Database, Business Directory, Download Archive, Documentation, and Pages. That should be enough to get you started with almost any project.
But if you need something special, Zoo is easy to customize. And you can build your own apps. Click here for a detailed review of Zoo.
The one thing I like about Zoo compared to K2 is the documentation. Zoo’s documentation is pretty complete; K2 documentation is very limited. Also, if you want to try Zoo for free, download the free version; it comes with a very nice blog.
acyMailing
acyMailing is a free, powerful, easy to use newsletter component for Joomla. The free version comes with most of the features you will need to manage a newsletter and mailing list on your Joomla website. It comes with a template for creating your newsletter or you can use existing Joomla content in the newsletter.
You can buy additional features if the free version does not meet all your needs. But I want to emphasize one of the most important features: it’s easy to use. I installed it for the first time and set it up in less than 30 minutes.