McKinley is an all-in-one studio for drawing and annotating SF Symbols. It bundles vector tools with knowledge of the SF Symbols structure, so you can edit one set of objects across multiple weights, sizes and colours. Import SVG or start from scratch, live preview your work using Apple’s own renderer, and export directly to Xcode, so you never need touch the SF Symbols app again!
…you might want to read the Introduction to SF Symbols page. It helps to understand Apple’s workflow for making symbols, even though McKinley’s way is much better!
For a whirlwind tour of how McKinley works and what it can do, read the McKinley Workflow page.
All this information can be found on the Exporting page.