Accessibility
https://wave.webaim.org/

wA11y – The Web Accessibility Toolbox

https://wordpress.org/plugins/wa11y/

OneClick Accessibility

https://wordpress.org/plugins/pojo-accessibility/

WCAG 2.0 form fields for Gravity Forms – requires gravity forms

https://wordpress.org/plugins/gravity-forms-wcag-20-form-fields/

Language Translation

https://wpml.org/

Polylang

https://polylang.pro/doc/

https://www.youtube.com/watch?v=IkUo7IE5ZRI