We have created a proof-of-concept “monitoring” app on non-jailbroken iOS 7.0.x devices. This “monitoring” app can record all the user touch/press events in the background, including, touches on the screen, home button press, volume button press and TouchID press, and then this app can send all user events to any remote server, as shown in Fig.1. Potential attackers can use such information to reconstruct every character the victim inputs.
via Background Monitoring on Non-Jailbroken iOS 7 Devices — and a Mitigation | FireEye Blog.
Before Apple fixes this issue, the only way for iOS users to avoid this security risk is to use the iOS task manager to stop the apps from running in the background to prevent potential background monitoring.
Yikes! This might be a problem for android devices as well. I have noticed that since a device stays on 24/7 resident apps can build up in the background because even though you think you closed an app it sometimes doesn’t actually close as in terminate until its icon is touched to activate. The proof of concept above got this “keylogger” through Apple’s App Store which is pretty remarkable.