Sure, but you have to include a link to Icons8 in your work. Free assets have limitations such as smaller sizes, select file types, or formats.

They both use the same asset collections. But Pichon as a desktop app is much easier to integrate into your workflow — you can just drag and drop assets everywhere. Also, you can use it as a personal cloud for your own assets.

Any of icons/illustrations/photos Icons8 subscription opens you a high-res images and vector formats for corresponding assets type.