It looks like thyme to me. Have you smelled it?

It's Lithodora diffusa, a low growing evergreen ground cover that has electric blue flowers. One often sees it in rockeries in this area....it likes that very good drainage.

Here is a link that might be useful:

OOoo, I'm glad I didn't pull it. That is a bright flower. I'd like to add some compost to the bed it's growing in, the soil here is very sandy. Will it be ok with that?

Likes a sandy soil. Don't dig in the soil and mix in the bark, in an attempt to incorporate compost. Instead augment and maintain the bark, or cover with another comparatively coarse mulch, like cedar play chips (I love the cedar mill by-product we have been getting on Camano Island). In nature organic debris falls on the ground and is decomposed and integrated by insects, fungi and bacteria, started at the surface. Mulching imitates this, unlike amending.

A coarser material like the bark is a better cover for the soil than a finer, more decomposed one like finished compost. Part of the beneficial influence of the mulch is due to difference in texture (particle size) between the mulch and the soil. A finer mulch is less effective, being of more similar texture to the soil beneath.

Shrubby plants such as Lithodora really hate damage to their roots, as is liable to occur when attempting to improve soil conditions for them by digging in compost around them.

The sheet of blue in spring produced by a large, healthy mat of Lithodora is wonderful. However, a blackening and decline similar to that also seen here on bearberry on some sites is common. If it begins to occur on your plants at some point, do not feel you are being singled out.

It also resembles a young Helianthemum plant, IMO. Experts?

Yes, to me it looks like Helianthemum.

Either way not a weed.

Hmmmm. Do they ever self-sow? There is a huge pink Helianthemum in another bed, about 30 feet away from this. I'll have to compare the two. Well, I may not know for sure what it is till next spring when it flowers. Glad I didn't pull it anyway. Thanks to everyone for the help.