Besides periwinkle (vinca), there's ivy (no flowers but there are some varieties with white marbling), lamium (dead nettle)(pink, white, purple or yellow flower depending on variety and some have a silver stripe on the leaves), snow-in-summer (bishop's weed), pachysandra, goldenstar (limited season bloom), or Geranium sanguineum Tiny Monster or Geranium Cantabrigiense Biokovo/Cambridge/Karmina/St. Ola (these are often lemony scented, bloom well all summer, and the leaves turn reddish in fall, and the plants stay low and do not flop and naturalize well... I use Geranium Cantabrigiense Karmina as a ground cover around my roses because I hate weeding around thorns). There's also chameleon plant and ajuga if you don't mind something invasive. Ajuga will easily get in the lawn despite any efforts to stop it.

I think all of these are pretty low maintenance.

Thank you.