California Baby

We have been using Klaviyo for about 3 years now and it's a great program. Pricing can be adjusted easily on how many emails you send a month and it's easy to build emails and analyze the stats after. If your account is big enough, they provide a customer success rep that will analyze your account and offer helpful suggestions.

This app is very helpful with providing order ETAs at checkout on product pages. We used to get a lot of customer service questions about when an order would arrive but those have stopped since we added Fenix. It is also easy to tweak the delivery ETA if your warehouse is backed up.

I am a big fan of Recharge. Due to the nature of our subscription program, we needed a higher level of customization and Recharge was able to provide that for us. Integrates easily with Shopify and they add new features to the program to increase UX which I like a lot.