Braintree

Braintree integration currently offers the following payment methods:

• Credit Card
• PayPal

Specific limitations:

• For Credit Card tokenization, the API needs an instance of BraintreeFragment which force us to use it from an Activity.
• Building a custom UI for PayPal is not supported.

Build your own UI:

For the Credit Card, Braintree integration supports building custom UI, whereas, for PayPal, Braintree integration currently doesn't support building custom UI, as most of the flow is handled by Braintree SDK which uses the browser to complete it.