London ( CNN ) -- For a few days , Lockitron looked like the little app that would , and should , but then could n't . Lockitron , which enables doors to be unlocked through a smart phone , was rejected by Kickstarter in October . It was turned away for being a home improvement product , which the funding platform does not support . But then Lockitron went `` DIY '' on its own crowd-funding . In one day , orders hit $ 500,000 . They are now sitting at $ 2.2 million , the equivalent of more than 15,000 units . Read more : 'Father of the internet ' : the case for online freedom . Lockitron creators Cameron Robertson and Paul Gerhardt were both University of Colorado students -- studying history , economics and finance , and computer science respectively -- when they started playing with inventions . When they came up with Lockitron , the response was enthusiastic . `` People gravitated toward the doorlock [ idea ] . People lose their keys , keys are copied , you do n't know if a number of keys are out there ... they are a lot of inconvenience , '' Robertson told CNN . The two , both 25 , had worked on a `` shoestring budget '' -- around $ 10,000 to $ 15,000 -- and a year 's worth of time to fund their creation , which first released in May 2011 . Looking back at that time , Robertson says they discovered that `` oatmeal for breakfast is wonderfully filling , and wonderfully cheap . '' The two `` kept living like college students , frugal college students . '' Feedback was `` incredibly positive '' and when they showed the product off at a party full of Silicon Valley investors , the warm reaction provided market validation , he added . Read more : Why are n't robots doing my dishes yet ? They turned to Kickstarter as the `` perfect venue '' to fund the project . `` We sent our application in , thinking that in short order we 'd be approved but that 's , of course , not how it turned out . '' After being rejected `` we went through the stages of grief and sadness pretty quickly because we did n't have time to deal with it , '' Robertson says . Ten days later , the pair 's own crowd-funding system was up . `` We had no idea what to expect in terms of traffic , '' Robertson recalls . `` [ We thought ] if we shot for $ 150,000 in 30 days we might be able do it ... and we had no other option . '' He credits Kickstarter for ensuring Lockitron had a well produced video , needed as part of the application process , which became a YouTube hit . `` It had just the right mix of excitement , and explanation of the product , '' Robertson says . `` It captured people 's imaginations in just the right way . '' Angel investors injected a `` few hundred thousand '' into the project last year , allowing Lockitron to launch its second , more streamlined version . The first version required the app , which needs to be signed into , to be tapped to open the door . The upgraded Lockitron senses the person 's proximity to the door and unlocks it once you are in range . It also allows people to unlock their doors from afar , ensuring guests are able to get in . It works with wifi and bluetooth , sending a signal to a physical block attached to the Lockitron owner 's door . If the phone is lost , the owner needs to sign out of the app for security beyond the phone 's log-in code . It works on a conventional U.S. deadbolt , which make up 60 % to 65 % of the market , and sells for $ 179 . Robertson said the company hopes to eventually expand Lockitron into UK locks and beyond . `` The timing was right for this sort of product because people have become so used to their smartphones and using apps , that it was a natural extension they should have an app for the key as well , '' Robertson says . `` A lot of people see the hardware and think that 's what we 've done but [ Lockitron ] is the combination of hardware and app and software , '' Robertson added .
Lockitron is an app that enables doors to be unlocked through a smart phone . After having been rejected by Kickstarter , the start-up managed to successfully raise funds online . Lockitron senses your proximity to the door , then uses wifi or bluetooth to unlock it once you 're in range .