Contributors mailing list archives
Re: Odoo11 GUI in Odoo 12 available?by
Tecnativa. S. L., Pedro M. Baeza
For both versions it's better to put https://github.com/OCA/web/tree/12.0/web_responsive, although the optimal experience is with v12, but you have to get used to have the menus on top, and use the search option for finding the menus. Not doing that is to fight against current, and not being mobile friendly.