"Adds on" is a common term used to describe additional features or functions that are added to an existing product or service. However, there are various synonyms that can be used to replace this term. Some examples include "extensions," "plugins," "accessories," "supplements," "enhancements," "attachments," and "modules." These synonyms may be more appropriate in certain contexts depending on the product or service being described. They can also add a sense of uniqueness and creativity, making the product or service stand out from competitors. In summary, having a range of synonyms for "adds on" can help expand one's vocabulary and improve communication.