I need help with ad hoc testing of an already xcoded ios app

I have had an ios app written for me a year or so ago but the developer has moved and I lost touch with him. The project has been dormant for a while but I have now been asked by a prospective client to provide a working version for a trial.
I need an ios developer to resend the xcode to one of my ios devices, an iphone 4s, either using Testflight or as an ipa file so that i can do some ad hoc testing.
After that,the code would need to be finessed and the app design improved to make it a marketable product.