So to answer the original question, both are a solid maybe. iPhone and Android based light meters can be used for constant lights - stuff you'd use to shoot video. Light meters that understand what a strobe is are worth their weight in gold, as it allows you to construct a photo, building an image in layers, and lighting each layer independently.
So the next question is if you need a light meter. Long story short it depends on what you're shooting. Light meters are used in fine art and portraiture, mostly when using strobes. If you do this style of photography AND you are doing off camera flash, then it would be a good idea to pick up a light meter. Otherwise, save your money.