Aimeos and the Aimeos Flow package are very powerful but there are numerous features that are only available through additional extensions. Often, your project also requires special features that makes it different from other web sites built with Aimeos. But extending the Aimeos Flow package itself is a bad thing because you will lose the ability to update the extension.
To solve this, the Aimeos Flow package allows you to integrate additional Aimeos extensions. Simply place your additional extensions in the Packages/Extensions/ directory of your TYPO3 Flow application.
You can easily create a new Aimeos extension by using the extension generator