Quicker is advanced WooCommerce quick check out plugin to add custom fields along with multi-step checkout, and set upsell and quick sell options.

FunnelKit Cart adds a beautiful sliding cart to your WooCommerce store. Let the buyers add items, edit quantity and add upsells on the side cart.

Create high-converting WooCommerce checkout pages, WooCommerce thank you pages & sales funnels with the highest-rated WordPress funnel builder.

Checkout Field Editor (Checkout Manager) for WooCommerce – The best WooCommerce checkout manager plugin to manage WooCommerce checkout fields.