You might want to consider doing some research on why Amazon owns app.guru, and if you're able to find contact info for somebody on their marketing side, pitch it to them. Do your research before you start emailing. If you're able to make reference to why they own app.guru (maybe an upcoming project?), you are more likely to get a response to your outbound marketing.
You might also want to consider reaching out to these guys:
http://www.appsguru.xyz/
I wouldn't ask for the world for your domain, but you should be able to pull out a decent ROI.