This is the 13890th most frequent Spanish word.
sobremanera
"Extremely" or "exceedingly."
In this context, 'sobremanera' emphasizes the extent to which the speaker enjoys the company. It modifies 'agradar' to express a heightened level of enjoyment.
Me agrada sobremanera tu compañía.
I greatly enjoy your company.
Here, 'sobremanera' is used to intensify the utility of the effort described. It functions as an adverb to enhance 'útil.'
Su esfuerzo fue sobresaliente y sobremanera útil para el proyecto.
His effort was outstanding and extremely useful for the project.
In this usage, 'sobremanera' conveys the strong degree of concern the speaker has, acting as an adverb to emphasize 'preocupar.'