Developer needed to finish a mobile app that promotes nightlife events

My company has been working with a developer over the last few months to build a nightlife app for the iPhone. The developer has dropped the project, as he was working in his spare time and work got to busy for him to continue. We have the app fully designed and laid out, the database completed and organized, and we need someone who is competent in iPhone and/or Android apps to come in and complete the remaining work in order to submit. The project essentially entails working in objective C to connect the database (Parse) to the app in the proper locations. Some additional design is also necessary, such as changing map icons according to a parameter, or changing the date for which events are displayed. The app is relatively simple, composed of 4 primary tabs, and no tab has more than 5 possible interactions, with the average being 3. It's designed to display information to the users in a convenient format (Similar to Urban Spoon). We have a working version currently, and pending further negotiations, this will be made available to you and you will simply need to connect the remaining portions, which is probably 15% of the total project. The most challenging aspect of the service is writing the code so that the events can be displayed according to different filters (time, location, features, etc). Please base your bids around 25% of what you would charge to build the app (a simpler version of Urban Spoon) from a completed design and functional database.