Like many of the apps-and-devices that exemplify the trend known as the Internet of Things, GasWatch bills itself as nothing short of a miracle cure for a supposedly harrowing first-world problem. “Peace of mind,” the Indiegogo campaign promises in the introduction to a litany of unattributed endorsements like this one:

My roommates and I were having a big party that night, and I was out at the store. We had a huge amount of food to grill, and I realized that I had no idea how much propane was left in our tank. None of my roommates were answering their phones, so I couldn’t tell if I needed to pick up another tank or not. If I had the GasWatch app, I could have easily looked up exactly how much gas we had left, since the app saves the last reading, even when not connected via Bluetooth to GasWatch.

If only! After all, GasWatch insures you never have to worry about propane again! “You won’t have to run to the store and get another tank in the middle of an event,” they promise. “No need to take up additional space by storing an expensive spare tank,” they assuage. It makes you wonder what we did before the Internet of Things came along to rescue us.

Except, it doesn’t. The truth is, there’s scarcely little that’s new about GasWatch at all. If you want to know how much gas is left in your standard-size, 20-pound propane tank, you’ve had a number of options for as long as there have been propane tanks. The simplest one, which costs essentially nothing, is to run a stream of hot water down the side of the tank. The portion of the tank with propane still in it will absorb the heat of the water, and the canister will feel cool to the touch. Starting at the bottom, just feel for the imaginary line in the tank where cold becomes hot, and there’s where the propane ends.

If you’d like a less laborious and more surefire way to check your grill’s horoscope, you can buy a gauge that screws in between the tank and the line. What’s it do? It’s a gauge. It reports the gas levels. The fancier versions have multiple markings for different outside temperatures (since the ambient heat around the tank can create different readings). It’ll set you back $5 to $20.

You can also buy a propane scale. Set your tank atop the scale, which is shaped to hold a standard propane tank. An analog or digital meter either shows the weight or translates it into the amount of propane left or the approximate cooking time that much gas yields. In fact, the GasWatch smart device is really just a digital propane scale with Bluetooth communication and an associated smartphone app. It turns out GasWatch has been making such devices (but, you know, “dumb” ones) for years—you can get one for about $25.

None of these methods is foolproof. The hot-water and line-gauge methods require you to eyeball the level and translate it into cooking time. And the scale assumes that a full propane tank weighs in at a specific and stable level. A tank plus 20 pounds of propane should weigh around 37 pounds (your tank’s tare weight may vary), but in practice a “full” tank might contain slightly less or slightly more depending on the temperature of the tank and the air when it’s filled, and the distractedness of the human agent doing the filling. Apps can’t help with that. Maybe soon, robots will.