While nowhere near as common as SQLite, you may come across mobile applications that are utilizing Realm databases as a means to store user data. Realm has been in existence since 2014; it is a non-relational database management system that stores data as objects, and it includes programming support for Java, Objective-C, Swift, and React Native.

It has been increasingly common to see Realm databases, especially on iOS devices, but while they may be included in the application directory, developers may still choose to store user-related data in their SQLite counterparts. Realm support has recently been incorporated into most mobile forensic utilities, but Realm Studio can be downloaded for free for stand-alone analysis of databases on Mac OS, Linux, or Windows. Files with the .realm extension will require analysis, with user data often stored in the default.realm file.

Realm databases can be characterized by these four bytes, 54 2D 44 42, which begin at offset 10 and end at offset 13.

Special thanks to the Cheeky4n6monkey for sharing a simple Realm database sample.

Reference:

https://for585.com/realmstudio (Download link)