How about a Community Buyout?

The developer obviously has no interest in supercoin anymore, he has been around... 
https://bitcointalk.org/index.php?action=profile;u=341100
Remember, supercoindev is actually good at communications, that is not the problem.
https://bitcointalk.org/index.php?action=profile;u=341100;sa=showPosts

By ignoring the project updates, roadmap, and forum questions, the market cap has been driven from $250,000 to $34,000 this month. a 7x loss...
There was even a request for help with a donation transaction that got ignored... It is obvious supercoindev has no supercoin holdings and has quit.

Since the project is still not really complete, and the anon transaction part is not making anyone famous,
Lets just offer the developer some bitcoin to open source it before leaving.
The price is sinking fast, this could be the last chance to do something before it becomes completely worthless.
Then supercoindev can remain anonymous, leave the project that has become boring, and make some coin out of the deal. 

This community would have no problems finding and crowdfunding a dev with QT experience to finish up the software and release it.

TLDR; Bribe developer to Open-Source the Super-Sauce!