Typeform is a very user-friendly form and survey builder. The design is clean and the features are smart: You can customize your survey in different ways, and you can also create lots of clever interactions using features like "logic jumps" which create unique paths of questions based on answers.
Klaviyo is the best in class email marketing solution for eCommerce. It's powerful because it connects to your store, and you can create awesome customer segments based on past purchasing behaviors, customer preferences, and even future predictions of spending.
Shopify is a commerce platform that allows anyone to set up an online store and sell their products. It's the go-to eCommerce platform for young direct-to-consumer brands. It's ease of use and setup is what's most attractive to merchants, but also the incredibly vast Shopify app store.