Build a Website - Social Medi Photo Contest

I want to create a website that has a fun style like [login to view URL] I iwll provide some elements that can be used to brand the site for my company. The primary objective of the landing page is to promote the photo contest, and allow users to upload photos into the contest. If possible, the users should also be able to submit photos for consideration by posting them to their favorite social media channel with a hashtag. If you are going to use a special program/software for this feature let me know what the service website is, and additional costs etc. please show me examples of your work AND any other photo contests websites you've created before.