Zulily has Halftees on sale for 50% off today. I own one and I love it! I wear it all the time under sleeveless dresses, lowcut dresses, etc. It's a staple in my closet.
And while you're there, check out the Sweetie Pie Collection sale. If you've got a family wedding coming up and you need a flower girl dress, these are super cute and 65% off.