This plugin aids with beta testing WordPress plugins hosted on wordpress.org. After activation of this plugin, you can choose the plugins to show a beta notification at the setting page. Then, WordPress will notify you of new beta versions of selected plugins, not just new stable versions, and you’ll be able to upgrade to these beta versions with just one click within WordPress.
Make sure to make frequent backups while you beta test plugins, and make sure to report bugs. Thanks for helping test plugins!