All payments are securely processed by Stripe, our payments provider. Stripe handles billions of dollars in payment transactions every year and is used by leading internet companies such as Twitter, Shopify, Slack and many more.
When you subscribe to one of our premium plans Stripe handles all sensitive data for us. Your credit card information is never stored on our servers. During the subscription process we don't even touch it. Your card information is processed by the Stripe payment form, which we just display within our app, and sent to Stripe using an encrypted SSL connection (https). You'll notice the 'Powered by Stripe' logo on the left corner at the bottom of the screen.
You can learn more about security at Stripe on their website.