Backend developer for an exciting mobile WEB app project, already on tracks

I am the founder of a company called adsy.me
we have already released an early beta of our exciting mobile web app on adsy.me on iOS (you can test it on your iphone / ipod touch with iOS6+).
We are looking for a new talented backend developer to be in charge of the connection between our frontend (state-of-the-art html5/javascript/css3) and our BaaS (currently Stackmob but we might change provider).
This is a long term contract, at least until August 15th, 5 days a week,
£300 per day ex VAT, invoiced on a bi-weekly basis.
We will only consider candidates with a mobile/web experience incl. a solid social component (user profiles, activity feeds, search-discovery (#, geoloc,...), OAuth with 3rd-party social networks & other apis,...).
We have a strong roadmap of features to be released by early August.

Please send me your resume incl. a portfolio showcasing recent work you've been involved with.