AS we already know Joomla is one of the most widely used content management system. We can easily manage the content of the site using Joomla's Article manager, ACL etc features.
Third party extensions makes Joomla even more powerful. There are many widely used extensions like K2, Zoo, etc. These makes the content management very easy. In this list Yootheme's Zoo extension stands at the top of the list. Zoo helps you to handle the content related to movies, applications, downloads data in very efficient way.
Few cases Zoo lacks the much needed features like Zoo Export/Import feature doesn't allow you to import large CSV files.
No worries thanks to the companies that have created out of box applications which helps you to solve such glitches. These applications just extents the Zoo native feature. These are the applications that you have to check if you gonna widely use Zoo extension in your Joomla site. Below is the list of companies their Zoo based applications that extends zoo and adds some awesome feature for your site.
Zoolanders is the name that I never imagine Zoo without it. Here you can find very advanced Zoo based applications like RI Pro, ZooPort. We have used RI Pro in our project to manage movie based records. Zoolanders support is awesome. They help not related with their products but also helps for Zoo related stuff anytime. Miljan is super guy.
I came to know about this site recently when I was looking for Zoo add-on. However JBZoo is not listed on JED so it takes time to find them. This application is for you if your site is dealing with very large amount of data which needs export/import on daily basis or even product comparison functionality, shopping cart etc. JBZoo allows you to add system events(triggers) of Zoo Framework and you don't even need to hack Zoo fields for it.
If you want to extent Zoo functionality for the features that Zoo lacks, first take a look on above extensions before customizing Zoo. It's always better to use developed extensions instead of writing our own code. You can extend Zoo functionality these third party extensions.