Technology moves fast, so it makes sense that sometimes big, innovative ideas don’t always deliver the goods. That could be because they were just too ambitious (read: ridiculously unrealistic), didn’t take design or hardware limitations into account, or ran into financial difficulties due to spending too much cash or not raising enough. 

There are a whole host of reasons why a fantastic idea, elevator pitch or crowdfunding campaign might never make it from the drawing board or initial prototype stage onto our wrists, heads and bodies. But what were the biggest disappointments that could have really caused a stir? And which similar ideas have stepped up in their place?

Let’s take a closer look at a few of the big, bold, potentially brilliant ideas that promised us so much and yet delivered so little. (As far as we know these have all been paused, paused indefinitely or are officially no longer a thing at all. But if you know otherwise, do let us know.)