JSXHint, a ReactJS/JSX Code Quality Tool Online
jsxhint.com
jsxhint.com
My tool of choice though is eslint and its react plugin [1]. Which seems to have some additional features like enforcing some best practises.
It's probably also worth posting this guide [2] from awesome Dan Abramov of how to setup linting for Sublime Text 3 and/or webpack.
[1] https://github.com/yannickcr/eslint-plugin-react
[2] https://medium.com/@dan_abramov/lint-like-it-s-2015-6987d44c...