Check this blog at the first. We've modified our problem selection process. Now you can use this form to submit ideas. If you submitted a problem on Ninja-Setters, send it again through this form, I can't access Ninja-Setters anymore.
Still, we're in need of approximation problems, please submit them if you have any.
If you have questions, please send an email to me (firstname.lastname@example.org) or ask in comments. Please do not message me here.