Park.io is the leading Backorder Service for .io Domains. You can now find the current Domain Auctions from Park.io on ExpiredDomains.net. They are public auctions, so you can bid for them if you want. You can also find pending delete .io Domains in the Pending Delete Domainlist.
In other news: Sedo changed something with the "Search API" I was using to import their domains into the Sedo Fixed Domainlist. This was an internal API the Sedo Frontend was using and unfortunately I'm unable to get it working again. As a result, the list will not be updated anymore and I will remove it soon.