The 2.6.0 version of letterforms for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The application is categorized as Design & Photo Tools. The actual developer of this free Mac application is Wei Jiuqiao. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
Letterforms lets you make your own creative variable fonts. With this application, you can create fonts of your own and export them. It supports variable fonts, touch-friendly vector drawing, kerning adjustment, scan of sketch photos, exporting fonts as TTF/OTF OpenType files, and more.
You may want to check out more Mac applications, such as Glyphs, which might be related to letterforms.