New version of JSON UDF functions has been just released. This is maintenance release which only contains fix for 4 bugs:
74090/19821398 `INSTALL_JSONUDFS` ISSUES A WARNING DUE TO TRUNCATION OF `VERSION_COMPILE_OS`
74091/19692634 `JSON_DEEP_MERGE`: DEEP CRASH IN `MERGE_TREE`
74092/19692628 CRASH WITH SECOND-HAND NULL IN PARAMETERS
74097/19693198 `CREATE_NEW_VALUE`: STACK BUFFER OVERFLOW, %LLD CAN'T FIT IN CHAR
Also 0.3 branch becomes stable branch and no new features will be pushed to this branch in future. Previous stable branch (0.2) removed from MySQL Labs website.
As usual you can download functions from http://labs.mysql.com/.