Based on our record, Kuzzle seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on Reddit, HackerNews and some other platforms. They can help you identify which product is more popular and what people think of it.
Also I recommend you to use foreign-key database structure, instead of documents. To my opinion it suits better to Parse Server. If you wanna use documents, you could try kuzzle also good solution! - Source: Reddit / 9 months ago
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
Parse - Build applications faster with object and file storage, user authentication, push notifications, dashboard and more out of the box.
Kumulos - Made for the business of mobile app development, Kumulos helps you manage the commercial and technical performance of Apps, so you drive a better outcome for your clients.
CouchBase - Document-Oriented NoSQL Database
Kinvey - Kinvey is a BaaS provider that makes it easy for developers to set up, use and operate a cloud back-end for their mobile apps.