We study the mean curvature motion of a droplet flowing
by mean curvature on a horizontal
hyperplane with a possibly nonconstant prescribed contact angle.
Using the solutions constructed as a limit of an approximation
algorithm of
Almgren-Taylor-Wang and Luckhaus-Sturzenhecker,
we show the existence of
a weak evolution, and its compatibility with a distributional
solution. We also prove various comparison results.
