We know there's still a lot to improve and to do in yCal. We continuously add things to our internal to-do list as we're using yCal ourselves on a daily basis. The lists of bullets below are not exhaustive and don't come with a guarantee that we'll complete these items in a specific time-frame... but they may give you an idea of a few things we're currently thinking about.
Update mid 2018: We've just updated yCal for MacOS Mojave, making sure it smoothly runs on the newest MacOS and fully supports new features such as the amazing Mojave dark mode. This has been the biggest overhaul in the last three years and should make yCal fit for a couple of upcoming MacOS generations again.
However, it's true that our update rate for yCal has been lower than planned over the last two years, and, most likely, will be low again for the upcoming months. The reason simply is that I've two little kids (two and five), and family business is still eating up my time like chocolate. Rest assured, though, that we remain deeply committed to updating and advancing yCal, and you'll continue to see bug fixes, adaptations to new MacOS versions, and new features!
Of course I'm also eager to receive your feedback and hear about your suggestions! So if you have questions, feature requests, or suggestions, please let us know!
Updated: Sept. 2018