Does CartStack Work Across Devices?

Yes, CartStack works across devices. 

We do capture email addresses on both computers and mobile devices. Let's say the customer enters their email address on their phone, abandons their cart, and switches to a laptop. After they enter their email address again on the website, our system will realize it's the same customer. 

So if a customer starts shopping on one device, and then completes their purchase on another device, our system will know to stop sending them cart reminder emails. Your site may or may not remember their cart items across devices though. So if they're not a logged in user, they might need to re-add items to their cart.