I tried several apps to manage metafields but this is certainly the most powerful.
I contacted customer support for a problem on my theme and I immediately received a response with the solution to several of my emails.
(written by Damian, a web developer)
Accentuate Custom Fields is absolutely brilliant. I honestly think ACF should be part of Shopify itself, it's so good. It's simple to use for the average user, but flexible enough to meet the needs of developers .
I come from a Wordpress background, and for a long time have used plugins like pods.io to add extra fields to Wordpress objects. Pods is fantastic, so I was curious to see if something similar existed in Shopify-land.
Shopify uses metafields to store data, but provides no user-friendly frontend to create or edit metafields. That's where Accentuate Custom Fields comes in. It lets you create all kinds of fields for a wide variety of Shopify object types, and provides a clean, no-nonsense user interface which makes data entry a pleasure.
Some of the field types supported include numbers, amounts, textareas, dropdown lists, checkboxes, files (such as images, or documents like PDFs) and colours (with a handy colour picker). There's also reference fields, which let you select an item from a list of Pages, Collections, and other shopify object types.
For developers, it's easy to display the contents of metafields on the frontend of your site with basic liquid tags. The Accentuate Custom Fields system was so useful I was able to build a pseudo page layout system for the theme used on a customer's website, which breaks each page down into blocks, similar to the way the Theme Customizer works in Shopify.
Without a doubt though, the most important feature of this application is not the software itself, but the people behind it. The developers have been very proactive and even suggested ways to make my life easier, given the way I was using their product, and came up with improvements in response to feedback I provided. It's support like that which makes all the difference.
This app is a must-have for just about any shopify store that could use customization. And at the price point it is being offered, including it in any project is a no-brainer. Do yourself a favour and give it a try - you won't be disappointed!
Honestly, I've only used this on products so far, but this seems like the best/least hacky solution for dealing with metadata that I've seen on the App Store. 10/0 would recommend.