Do you have custom components in Fritzing format? It's now possible to import fritzing parts into Layout mode of Circuit Canvas:

By the way - Fritzing writes on their website that their parts can't be used in other software and I respect that. So this import feature is meant for converting community parts that are shared openly or parts that you've made yourself, not for Fritzing's original parts.

I've also made a converter tool so you can convert to Circuit Canvas format, then make edits to it if needed.