That looks like a Tradescantia or Spiderwort.  This is a perennial plant that will return year after year if you let it die back naturally in the winter. Then cut the stem and leaves off at ground level in the early spring and new growth should appear. The blooms come in white, pink, purple and lavender depending on the variety. I have one in my garden and enjoy the unusual leaves. Keep growing, Marianne Binetti