Hello,
I just read the description about your project and understood that you are looking for someone to design UI/UX for a collaboration platform (mobile, tablet and web)
I am a skilled developer and designer that have an extensive experience in App Developer, Wordpress/Woo-commerce, UI/UX, Wix, Weebly, Shopify, Bootstrap, HTML5, CSS3, and PHP/MySql.
My Portfolio: https://www.freelancer.com/u/dirksaikat
Looking forward to discuss it further via chat.
Regards
S.M Rafiqul Islam