Here's my recommendation for favorite Marketing automation tools that you can download from the Shopify store: 8 Best Marketing Automation Apps for Shopify
By reading the article you'll get detailed reviews of each app too. Wish you all the luck with your online business!
I suggest you try BestPush - Smart Notification. It is a smart web push notification service that automatically sends personalized push notifications to the shop visitors, whether they have added anything to the card or they only surfed the shop and left it without adding anything to the cart, but it seems they are interested in some products.
That is very useful and fantastic because it can manage discounts, too! It only sends the minimum discount possible to price-sensitive users and can drive more sales.
I hope you find it helpful!