I'm looking for some gui client for cassandra (like sqlDeveloper) to invoke some basic methods, and run cql queries
Dbeaver in its free enterprise version (not open source) is good GUI client for Cassandra. No need of installation. Its portable. Also this client supports more than 20 databases.
Try the following GUI client also
Check out Helenos - it's a simple web based tool. Cql is now supported (from Version 1.3).