Has anyone tried the tommee tippee groclock sleep trainer?

Yes. Have been using it for ages. Maybe longer than a year. It really worked for us. We started to gradually move the tine to the tine we wanted her to wake up. If she now wakes before it's on, she normally looks at it and goes back to sleep.

I started using it when my son was 14 months. He now plays happily in his bedroom until he sees “yellow sun” 😂

We have a version of it off Amazon (cheaper but same) and it works. He knows ‘red stay in bed’ ‘green means wake up’

I wanted to use one then read about children feeling lonely waiting for the clock to go green when all they want is to see their parents so it put me off hahaha