Sharing any file is as easy as just dropping it on the Swiftdrop dock icon and pasting the link wherever you want to share it. You can share multiple files/folders at once (the files will be compressed into a zip archive). It's possible to drag a file or image from any app that supports drag and drop onto Swiftdrop.
Swiftdrop is available as a download directly from the Mac App Store.
Other similar services require you to pay them for the storage or display ads in conjunction with your shared files. We think you should be able to use the existing cloud providers that you already use and love! Therefore, you can choose between sharing files using Dropbox or Google Drive™. Don't already have an account? Both services offer free accounts with plenty of storage!