We've released a new version of our EZ Mailchimp Integration addon that fixes some PHP 7 compatibility issues and also adds support for Mailchimp Interest Groups. The current version is 4.3.35 and is compatible with all V4 versions of cs-cart.
As usual, if your license is valid you should be upgraded to this version automatically. Unfortunately we do not intend to provide PHP 7 support for our V2 anv V3 versions of EZ Mailchimp Integration.
All of our other addons are compatible with PHP 7.