If you dream that a frog ate your phone, it can mean you were using your phone excessively. You may have become too attached to it and you fear something might happen to it. You’re losing your confidence because you had depended on your phone excessively. This dream that a frog ate your phone, has used unusual dream imagery but the symbolism is there.
A second tier of meaning can be derived by looking at the dream symbol of the frog, an amphibian which croaks. It makes noise, just like a person who talks too much on the phone. The frog may have eaten your phone to prevent you from using it. Perhaps the frog felt threatened by you, who was the other living thing that talked too much.
In your real life, do you know someone who talks a lot and may be your competitor? If yes, that person could be represented by the frog in the dream.