An idea has not any value. Someone doing something similar with what you think doesn't mean you can't succeed. What is important is the execution. Look at Uber

An idea has not any value. Someone doing something similar with what you think doesn't mean you can't succeed. What is important is the execution. Look at Uber, there is still companies lunching to be their competitor, some are succeeding, some not. If you want to work on this idea, forget about the competition. Meet with customers, are they willing to buy your product ? if yes, then you can succeed. What is important is building something, meet with the market and iterate