This exploit was recently discovered to take a screenshot of Snapchat photos without it notifying the sender that you took one:
SnapChat is a picture-chatting app for iPhone which lets you control how long you want your friends to view your message. For instance, you can send a picture to your friend with some text added, but your friend will be able to see it for only 10 seconds at most.
“That’s so easy to bypass. Why not just take a screenshot?”
Well, the app also alerts the sender of the message if the receiver tries to take a screenshot of the picture. So, how do we bypass it?
Before starting on with the guide, you need to jailbreak your iDevice. If you have already jailbreak-ed your iDevice, skip to step 3.
**Note: Must be jail-broken for this to work **
1) In Cydia, go to the search button on the lower corner of right and search for Activator.
2) Select Activator and then select Install.
3) Select Confirm.
4) When it’s done, select Restart Springboard.
*Activator gives you the ability to change the function of a particular button. What we are going to do here is use Activator to change the action of Volume button, so that you can press it to take the screenshot. SnapChat does not monitor your taking of Screenshot, it only monitors whether you have pressed the Screenshot button (Home and Sleep at once) or not. Thus, by using volume button to take screenshot we can easily bypass the screenshot alert message.
Here’s what you need to do next in order to configure the activator*
5) Find the Activator app on your Springboard and open it.
6) Select In Application.
7) Scroll down till you find Volume Buttons and then select it.
8) Select Down Short Hold.
9) Now, scroll all the way down to Take Screenshot and select it.
Done. Now, you can exit Activator.
Press down the volume button (minus) when you are in SnapChat (or any other app) to take the screenshot. SnapChat will no longer alert your friends!