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.
Back4App - For devs, by devs. An easy way to build, host and manage Apps using the open source Parse Server. Scalable Servers, Pre-build examples, Cross-Platform support
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.
Azure Mobile Apps - Build engaging cross-platform and native apps for iOS, Android, Windows or Mac with Azure's Mobile App Service.
CouchBase - Document-Oriented NoSQL Database