You've Been Left Behind will allow you to leave messages after you have been raptured - for $40 of course. I would hold onto your money because no Christian is being raptured until things are quite messy.

(Matthew 24:24-31) For false Christs and false prophets will appear and perform great signs and miracles to deceive even the elect--if that were possible. See, I have told you ahead of time. "So if anyone tells you, 'There he is, out in the desert,' do not go out; or, 'Here he is, in the inner rooms,' do not believe it. For as lightning that comes from the east is visible even in the west, so will be the coming of the Son of Man. Wherever there is a carcass, there the vultures will gather. "Immediately after the distress of those days " 'the sun will be darkened, and the moon will not give its light; the stars will fall from the sky, and the heavenly bodies will be shaken.' "At that time the sign of the Son of Man will appear in the sky, and all the nations of the earth will mourn. They will see the Son of Man coming on the clouds of the sky, with power and great glory. And he will send his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of the heavens to the other.

You gotta have "the Son of Man coming on the clouds" before Christians are raptured out of here, and, by then, it is too late for anyone left behind. Upshot; bad theology and a waste of money.