We have developed a checkout library that requires slightly more configuration when installing than a plugin created for a specific eCommerce platform.
The Checkout Library allows merchants to either add a [Pay with Splintr] button anywhere on their site to immediately launch a Splintr overlay with a checkout flow. Through this flow, the customer can create an account with Splintr or login, select the payment plan that they would like, and go through our credit assessment process to be approved or declined. This method is especially useful for merchants who may not have an integrated checkout on their website.
The second option that the Checkout Library supports is integration with your checkout to show a Splintr payment method as an additional option next to credit cards, for example. Once Splintr is selected at checkout and the customer continues, the Splintr overlay will appear.
Both options require your developers to create a customer checkout object with a number of data elements.