The ice fishing tip up is just a simple device that even the laziest of ice anglers can master.
What is basically is, is a levering device that has some fishing line and a hook attached to it. You can just set it and forget it because once a fish come along and gives it a nibble, the tip up, will tip a flag up, revealing that there is a fish on the line.
One down side to using a tip up is that it takes all of the fun out of fishing. With out the feel of jigging some bait on a line, you are pretty much just watching a hole in the ice. You don't even have to watch the hole of you are using this ice fishing device, you can just wander off and as long as it is secured to something, there will most likely be a fish on the end of the line when you return.
I can also imagine that many anglers have lost their tip ups to the big fish that they weren't expecting to find under the ice. I biggie could grab the hook and if the tip up isn't secured properly, that monstrous fish is just going to pull your gear down below the ice with it. This would suck for both you and the fish because you would loose some sweet gear but the fish would be stuck to an under water anchor.
Ice fishing tip ups come in many different shapes and sizes, with the most common just being the plain wooden lever. There are also more advanced electric tip ups that will actually cover the hole and provide a little bit of heat in the ice fishing hole in order to prevent ice from building up. That is probably the sweetest thing that I have heard about recently.