You download Snaphack from the iTunes store for $0.99. You log in with the same account you use for Snapchat. When you receive a Snapchat, you open the message in your new Snaphack application—and you'll find the Snapchat has repopulated there without a timer. It stays there for constant viewing.
Obviously, this has serious implications for the kind of stuff that typically gets sent around Snapchat, which seems to be creator Darren Jones' intention. From Business Insider:
SnapHack was created by Jones, who has created a couple of apps under DAP Logic. A few months ago he launched Iconical, which let users customize their iPhone apps.
Currently, SnapHack retails for $.99. Jones says he hasn't heard from Snapchat yet about his creation. He says he's already submitted an even better version of SnapHack to Apple, which will let Snapchat recipients forward the saved photo messages to friends.
We tried out SnapHack and true to Jones' word, it saves all photo messages you receive on Snapchat forever.
And start the countdown to Apple removing Snaphack in 5, 4, 3, 2, 1…
[H/T: Business Insider]