To build a client is relatively straight-forward. It should take you between 4 - 8 weeks of development work depending on the number of screens you will be need. You need to add some time for Graphics but you could do this in parallel.

Or you could buy a template and work on top of it which should save you some time http://www.binpress.com/app/social-iphone-app-design-templat... http://www.binpress.com/app/social-share-iphone-app-template...