1. Firebase 

Firebase is the best choice for React Native Apps. If your app uses more offline features such as offline data updates and syncs, Firebase is the Right choice for you. Google owns Firebase.

By using Firebase with NoSQL, one can easily manage MVC-based apps. The best advantage of using Firebase SDK is that the user will get automatic app updates.

Advantages

• Easily accessible through phone.
• Perfect for real-time offline data using apps.
• Allows Real-time data sync for all users.

2. Realm

The Realm is an open-source, Object-Oriented database. Database Realm offers ten times faster performance than other relational databases. In addition, it supports intricate data types for offline and real-time apps.

Developers choose realm databases to enhance the performance of React Native App.

Advantages

• The Realm includes a significant number of APIs.
• Realm uses Multiple encoding standards.

3. Watermelon

WatermelonDB is also a widely used Database for React Native Apps. Watermelon Database is built on SQLite and offers exceptional performance.

WatermelonDB handles data in low-end devices perfectly. It can also manage highly cached and multithreaded async functions.

Advantages

• Static typing with the flow.
• Allows simple data plugging.

4.  MYSQL 

MYSQL is a popular Mobile App Database. The thread-like memory assignment makes it quicker compared to other Databases. Also, MYSQL is super compatible with React Native and includes libraries to help developers use SQLite.

Developers can also use AsyncStorage to save data locally on the app device.

Advantages

• MYSQL is the most preferred and desirable database in the finance and
  banking industries.
• It includes a password-enabled encoding system securing multiple
  security levels.
• It has a host-based authentication feature making it more flexible.

5.  Pouch

PouchDB is an open-source Javascript Database. PouchDB maintains data in JSON formats. PouchDB allows apps to save locally on the device and sync it online on the compatible servers when the network connection is available.

Data protection is easy with its built-in authentication system.

Advantages

• It allows developers to integrate data with any supported server.
• PouchDB supports SSL, which implies developers can easily encode data
  with AES256.