So you have a really cool idea for an app, game, or solution to a problem. You get super pumped about it and start researching your idea, then the unexpected happens. You find out that somebody else has came up with the same idea and they have already produced it. This is always a downer and I am sure that everybody has felt this at least once in their life. Being a developer this has happened to me more than once, ranging from ideas about websites to potential phone apps.
A friend and I recently participated in a local hackathon. We had a general idea about what we wanted to do, we even had a handful of other people join our team which was really nice because we didn't think anybody would be interested. About half way through the day we googled our idea and it had already been done. This discouraged our teammates from wanting to move forward with our idea and they started formulating other ideas. My friend and I decided that we wanted to keep going forward with our original idea because we saw value in it. A few people went to other teams while others decided to call it quits. Long story short we ended up developing a really cool interface for the app, visualized the data better, gave it more of a local feel, and had it working right before presentation time. We ended up placing first place which we really didn't expect because the other teams had some really amazing apps by some really creative and talented people. The moral here is that if you have an idea, just because your idea has been created by another person doesn't mean that you should get discouraged and put that special idea in the past. There are ways that you can create a better product, save time, and ultimately make it cheaper.
It is all in the way that you look at this type of situation. It can actually be a good thing that your idea already exists. That means that at the very least, one other person in the world came up with the same idea. They might have came up with it early than you but this means that other people either have the same problem or want the same game and there is at least some kind of market for it. So right off the bat you know that you have a potential audience that you can target. If the other product has reviews online, this gives you a good jump because you can improve the negative things that people don't like about the current product as well as make sure your product has the positive features or features that people want to see. This all depends on how many reviews there are and how thorough they might be. You can also test out the current product to see what you think you can add in your product to make it better. By this I don't mean ripping off every feature from the product but you can test the product and treat it like an early prototype to your own to see what features you want to add or in some cases you might want to change or take away certain features. This allows you to build your product better and cheaper the first time around giving consumers a reason to use your product over the others. You can make your idea really stand out not only by making it function better but my making it look better as well. If your product is an app or website then you can polish it by giving it better graphics and a better user experience.
Make sure that everything you do to your idea is something that you want to do. As with anything, it is a lot harder to work on something you don't care about or see no value in. Ideas that you come up with and decide to carry out should ultimately reflect what you want and there is a very large chance that a multitude of people want the same thing. Ideas that you come up with and decided to turn into a personal project are really meaningful so it shouldn't matter if other people like or hate them, find value in them or contain no value at all to other people as long as they contain value to yourself. These are your personal ideas, your projects, and your way of solving a problem. If you don't carry out your ideas, thats when they are of no value to anybody. Do it anyways.