Hi,
I've been spending quite a bit of time updating Xcode projects to Swift 2. As you have probably discovered already, Xcode's automatic conversion to the latest syntax is a bit hit-and-miss! I've found particular problems with Bluetooth code (where some message signatures have changed), and the documentation has not entirely kept up with Swift's rapid pace of evolution.
However, it is all achievable, of couse, with care and attention. It will help if you have good test data. If your project isn't too big, I think we can achieve the upgrade within your budget.
I develop apps for iPhone/iPod Touch/iPad running iOS 9, using Xcode and Swift.
You can see some examples of my work, and client reviews of my completed projects, on my Freelancer profile page (under "portfolio").
It looks like you are new to Freelancer, so it's important to be clear on the details of how projects are managed, before going ahead. If you'd like to respond to this message, we can discuss things further, then you can make an informed decision on awarding the project.
Best Regards,
- Rob Dixon.