I have just launched OpenType.tools
as the online/next-generation replacement of my previous OpenType Features Editor application for Windows. For this initial launch, the website will generate a features file from an uploaded AFM, based on naming conventions of the glyphs in the font. The site is free and does not require registration.
Please check out the site
for more information and give it a go. I'd love feedback so I can continue to improve the logic that builds out the feature rules and add the features that type designers want. My aim here is to develop and share a set of useful tools for type designers/developers.