I have added the tag "hreflang" on every page and it works OK but I have to add the label on the homepage too.

You can add these tags?

<link rel="alternate" hreflang="en" href="http://www.todogadget.net/en/" />
<link rel="alternate" hreflang="es" href="http://www.todogadget.net/" />

Thanks
Regards