I think that you should set a deadline in order to make a general time frame for designers to get their designs in. You can always extend this deadline if needed. Otherwise, the contest could go on for a very, very long time. I might enter if I have time, hope you can find what you are looking for!
Agree, In order those have a doing and sumbit the works on right time. Then project have a plan for each road map. So is are best way to make a project to reach goal.
Can I join to this project SIGNATURE CODE ??
Sure you have right to join the contest signature, and make sure you app not out line of rules campaign signature.
Save this, perhaps as a reminder and useful in the future
https://bitcointalk.org/index.php?topic=484259.msg5393088#msg5393088 Goodluck.