Sendvio: Email & SMS Marketing

Wow! Really satisfied with the app. Definitely worth the $8/month.
Email templates are easy to customize (to customize it 100% you need to know to write/change the code a little, but small learning curve).

We're using Shopify PRO plan (which has cart abandoned cart recovery option) but it's very poor: with this app you can customize e-mail templates + set the time frames + you can send multiple emails + you can track the carts so you have a good statistics.

Recommend 101%