What are some alternatives?
When comparing Marvel (Comics) API and GlobalComix, you can also consider the following products
Comixology Unlimited - Netflix for comics and graphics novels by Amazon
Tapas - Tapas – Comic, Novel and Stories is free to use digital comic application by Tapas Media that puts tens of thousands of comics and web novel on your mobile device.
DC Universe - The DC Comics streaming service w/ original content
webcomic.app - Add motion and sound to your webcomics.
LINE Webtoon - LINE Webtoon is a digital comics platform with various comics for free on web and mobile.
Piperka - Webcomics listing and subscription manager