I don't think you should drop an "idea" just because the space is crowded or commoditized so long as the problem in the space has not been "solved." Consider t

I don't think you should drop an "idea" just because the space is crowded or commoditized so long as the problem in the space has not been "solved." Consider that there were many search engines before Google and many social networks before Facebook and so on. All spaces are crowded but there is still lots of room for improvement. Even a simple todo app doesn't do quite all the things everyone needs. You can imagine super versions of a todo that automatically uses your calendar to allocate time to the tasks. Then when people want to meet with you, it show you options that are spaced so you have time for your tasks and then analyzes the tasks you do and don't get done, and notices what the differences and then allocates the right time for the right task (morning for creative, night for braindead, lunch for meetings) or whatever. The problems are the same problems. Just look at the current solutions and you can see they are lacking. Then the question is, can you find a good way to solve them. (You code up the above solution and simply doesn't work, for example. )