Create a Financial App for IOS and Android Users

I have a requirement to build a Financial App. It is based around expenses, timeframes and projections, however, it isn't too complex. I would like to produce a Lite and Full paid version for both Apple and Android systems. I have a some screen layouts and design ideas but will need someone who can build an end solution based on that information. I am looking for someone who is able to interpret these ideas and produce an attractive and functional App. It would be preferred if you can supply a portfolio or sample of previous (similar) works. While your English should be good it is probably more important that you can produce professional looking results. You will be required to sign a confidentiality agreement prior to commencing the project. I would also like to know if you would be interested in reducing the original quote price for a contracted % income of the sale of the app? This would be my preference. Please let me know if you require any further information to provide your quote. Thank you.