I have experience with:
working with libraries and frameworks
Design and development together: I can code prototypes, create styleguides using specific frameworks, and ensure that functionality/design is as intuitive as possible.
I need to know what tools you're using at every level of the stack
Your requirements/limitations right now
Nature of the arrangement -- are you looking for project-based or ongoing work?
I typically charge hourly for this service, but I can also offer the package rate depending on how time consuming the project will be.