GasWatch [$25] provides a simple solution to a very frustrating problem – running out of propane in the middle of a cookout. The display shows the percentage of gas and the cook time remaining based on the weight of the propane tank. The GasWatch digital propane tank scale also includes a low level alarm that sounds when the tank weight is at 20%, 15%, and 10%. Just sit the tank on it and attach the electronic read out and that’s it.

Buy: Amazon