A simple tool that I use to convert my scanned film photos to the Instagram-friendly square format (by adding extra space to the sides instead of cutting off the content). Currently it's only supporting photos with an aspect ratio of 3:2 (standard 35mm format).
Another possible usage is converting images to the Instagram story format (using --format story). The result is a 1080x1920px image with white background. The photo content occupies 90% of the image's width. The aspect ratio requirement (see above) still applies.
The tool is implemented as a Swift package so that it can be installed using Mint and used as a command-line tool. ImageMagick needs to be installed prior to using the tool (brew install imagemagick). This is not a showcase project, there is no proper error handling or tests.