Braintree Payment Gateway Extension for Lifeline Donation Plugin
However, we don't need 100% of what the plugin does but it's well documented and the developer is very responsive. A truly excellent value (we paid for the bundle version and are glad we did.)
Lifeline Donation is a powerful plugin that I use as well as all its addons. In my experience, the support provided by this plugin is among the best I have ever received. Always very helpful when needed. You can't beat a Lifeline donation all around!