An unresponsive iPhone or iPad home button literally makes these devices useless. I was having this issue with my iPhone4 for months – seemingly without remedy – yet it was not an obvious fault. Sometimes it would work, other times it wouldn’t. Usually when I was pressed for time.
Using the lock key would sometime fix it but this was unreliable. I was spending long fruitless minutes of my life pressing a button, trying to swap between applications, to the point where I thought using a hammer may be beneficial, at least to diminishing my immediate frustration with the thing. Apple needs to work a bit harder on smoothing out this obvious design flaw.
Pondering sending it in for repair, I ran a quick search via Google and came across a range of potential remedies involving lengthy and warranty-breaking techniques! People pulling their iPhones apart to defluff the button– poking around with screwdrivers– even spraying WD40 on it!
Thankfully I found this built-in solution and am happy to say it works. Hope it helps you too.