Lithium Pro is a premium upgrade for the free Lithium app, designed to enhance your reading experience. This app unlocks advanced features that are seamlessly integrated into the main application. With its powerful synchronization capabilities and customizable interface options, it offers an elevated level of personalization and convenience for avid readers.

Key functionalities include Google Drive sync for data backup across devices, custom themes for personalized aesthetics, and additional highlight colors for better organization. These features collectively provide users with a more versatile and engaging reading environment.

Ideal for those who frequently switch between devices or desire a tailored reading setup, Lithium Pro ensures your library and preferences are always up-to-date and visually appealing. The ability to customize themes and utilize enhanced annotation tools adds significant value for users seeking a more refined digital reading experience.

The Lithium Pro app boasts an array of sophisticated features that significantly enhance the core functionality of the free version. One of its standout capabilities is the automatic synchronization feature, which utilizes Google Drive to maintain consistency of user data across multiple devices, ensuring you can pick up right where you left off.

Another remarkable aspect is the custom themes feature, allowing users to personalize their reading interface by adjusting background colors, text colors, and link colors. This level of customization extends to creating, editing, and deleting themes, giving readers unprecedented control over their visual experience. Additionally, the app provides an expanded selection of highlight colors, enabling more nuanced note-taking and content organization.

These features work in concert to create a more immersive and personalized reading environment. The combination of cloud synchronization and interface customization makes Lithium Pro particularly valuable for users who demand both practicality and aesthetic flexibility in their digital reading tools.