Which platform do you prefer?
Which platform do you prefer?
Another point is that issues are useful if shared. I shared links to issues to customers and coworkers countless times and included them in reports. A web client solves at least one problem, maybe two. First, they might not want to install (or pay for) another tool. Second, Ship references issues with the ship:// url, which won't work unless you have Ship installed. A https:// url would work for everybody but then you need to share two different URLs which would be cumbersome. I'm sure you already found a solution to that.
Your site doesn't address explicitly one fundamental aspect: the data are hosted on your server, like issues stored in GitHub, Jira, etc and you're selling the service, or will be. Is this correct? What's the pricing? Thanks.
At my current company we have an in-house project/issue tracker system which isn't quite as good as Apple's IMHO but very customized to this company's workflow. For my at-home consulting projects I try various web apps, most recently Mantis.
If you are planning on expanding to other platforms (iOS and Android, especially), maybe considering going with a C#/Xamarin-based project. It'll save you a lot of work by allowing you to re-use the underlying code for your app(s).
But disregarding my preference, what is your analytics showing in terms of OS usage?