I’ve mentioned a number of projects providing custom pull-to-refresh implementations most recently this component with easily customizable animations based on a set of drawing coordinates provided in a plist file.
Here’s a nice example from Yalantis of a custom pull to refresh implementation that animates and expands at the top of the view when pulling called Pull To Refresh Rentals.
PullToRefresh Rentals uses 3 images for the background, foreground, and sun images that you could customize to quickly change the look.
This animation from the readme shows pull to refresh rentals in action:
You can find Pull to Refresh Rentals on Github here.
A nice custom pull to refresh example.