What steps should I follow after uninstalling the Accessibility App for Magento?

No further steps are needed! Once the Accessibility Toolkit app is uninstalled from your Magento store, all associated data and configurations are deleted. You’re free to carry on with your store as usual. If you’d like to reinstall, simply find it in the Magento Marketplace and add it back to your store.

You can install Accessibility App from here.