Is there a free software addition to SQLite available for data-replication?

Berkeley DB's SQL API is completely SQLite compatible and offers HA/replication for high availability. The combination of SQLite's easy-of-use and Berkeley DB's scalability and reliability are a great combination.

Disclaimer: I'm the Product Manager for Berkeley DB, so I'm a little biased. However, one of the main benefits of adding the SQLite API to Berkeley DB is that SQLite applications can now have HA/replication for mission-critical, highly available applications.

Yes, there are some:

• LiteReplica (Single master)
• LiteSync (Multi-master)
• AergoLite (Blockchain based)

They are additions to the SQLite3 code. The interface is unchanged so we don't need to change the application code.

Disclosure: I am the creator