unidentified plant (succulent?)

unidentified plant (succulent?)

Observation - unidentified plant (succulent?) - UK and Ireland. Description: Very low-growing (up to 2-3 cm tall), creeping plant with veinless leaves. Flowers tiny (

Very low-growing (up to 2-3 cm tall), creeping plant with veinless leaves. Flowers tiny (

This is probably something really common that I've never noticed before, but it's annoying me immensely. Help?