Can I customize the available statuses?
I'm sorry, but we only offer the fixed statuses. Keeping things simple is one of the core ideas behind the simplicity of Sifter.
Having tried many different workflows in the past, it was frequently unclear which status was appropriate for an issue at a given time. As a result, we decided to keep the explicit status field very simple and, instead, focused on leveraging the other attributes like assignee and milestone for communicating other facets of the status.
For instance, for determining if an issue is "In Progress" or "Accepted" you could look at whether it's been assigned to a milestone. We consider any issue that isn't assigned to a milestone to be "Unplanned" or "On Hold". You could use priority or assignee in a similar way.
If you're interested in a more detailed explanation, we have a blog post that explains how we arrived at the statuses that Sifter uses.