I like the typography, the full lowercase and bold/non-bold font, as well as the iPhone App look'n'feel of #20.
However, the logo icon looks more like a muffin or cupcake than a tartlet (which is usually flatter and without cream). Tarts are usually fruity and have a flatter base, and it would be great if your logo icon could reflect that.
Thank you for your submissions and I look forward to some updates if you have some time!
(This comment applies to both entries #23 and #20).