Hi there,

One of the easiest and highest leverage plays you can make in your Klaviyo account is to add a Shopify app or two that supercharges what's already there.

Here are our favorite apps to add, in no particular order.

Retention.com or Wunderkind

An identity resolution tool that captures emails of people browsing your website who aren't on your list.

Our clients typically see a 20-40% lift in abandonment flow revenue after adding one of these, plus an additional 1,000 to 5,000 new subscribers per month.

Alia

The best and most advanced pop-up platform in ecom.

They build and design the pop-up for you. Their gamified formats like scratch to win, spin the wheel, and questionnaire pop-ups are some of the highest converting we've seen. Just check out their website.

RetentionX

If you want deeper analytics on your Shopify brand, RetentionX is one of the best places to go.

Customer lifetime value, cohort analysis, repurchase rates.

Maverick.ai

Helps your emails land in the Primary inbox instead of the Promotions folder.

We routinely see 10-15% higher revenue per email campaign when we use Maverick.ai for our clients.

Aftersell

A post-purchase upsell tool that offers complimentary products or higher quantities immediately after checkout.

A straightforward way to increase AOV with zero additional ad spend. The customer is already in buying mode. Aftersell capitalizes on that.

PostPilot

Direct mail postcards sent inside your customer's package.

A personal touch outside of the inbox that increases retention and LTV. In a world where everyone is fighting for inbox attention, a physical postcard stands out.

Fondue

Instead of offering a traditional percentage or dollar off, Fondue offers cash back.

Not all customers redeem it, which means more margin stays in your pocket. You can also incentivize customers to take store credit instead, which drives a second purchase faster.

Smile.io

One of the easiest and best looking loyalty rewards programs you can add to your Shopify store.

Integrates smoothly with Klaviyo and Shopify. If you want to build a loyalty program without a heavy lift, we'd start here.

Wonderment

Recreates your post-purchase transactional emails inside Klaviyo with your brand's own design and personality.

Also gives you custom tracking pages and messaging for any fulfillment hiccups. Your shipping confirmation emails should look and feel like your brand. Wonderment makes that easy.

Dataships

Adds a consent widget to your Shopify checkout that helps you collect more email and SMS opt-ins at checkout.

It makes sure those opt-ins are compliant with privacy laws depending on where your customer is located and syncs them directly into Klaviyo. A really easy way to grow your list through your checkout page.

You don't need all 10 of these at once.

Pick the one or two that address your biggest gap right now and start there.

Hope this helps.

Best,
Luca

P.S. If you're not sure where to start, Retention.com and Alia are the two we add first in almost every new account. Identity resolution and a better pop-up are the two highest leverage plays for most brands at scale.

Free Resources

Resources to help you scale

Use these resources to help improve your brand’s pop-ups.

  1. 100-Page Email Marketing Guide (2026)

    The complete playbook for email marketing across flows, campaigns, list growth, and deliverability.
    Get the Guide

  2. Pop-Ups & List Growth Guide

    A complete guide on building pop-ups that grow your list and convert more visitors into subscribers.
    Get the Guide

  3. Email Marketing AI Assistant (Custom GPT)

    A custom GPT trained on Grow Pronto's frameworks and content. Use it to generate campaign ideas, write email copy, or get answers to any email marketing question.
    Get the Custom GPT