Guest Mode on LG G2 is a separate Home Screen showing the applications, you have already approved. The Guest Mode is enabled with a specific pattern and the following is a step-by-step guide to setup Guest Mode on G2:
0. Make sure you have set Pattern as the lock screen method (To change the lock screen on G2, go to: Settings > Display > Lock Screen > Select screen lock > Pattern)
1. Open Settings, go to General and then open "Guest Mode" under Personal settings
2. Mark "Use Guest Mode" to enable the mode
3. Tap "Set Pattern" to set a specific pattern, so the screen will unlock to Guest Home Screen if that pattern is drawn
4. Tap "Set Apps" to add/remove the allowed application in the Guest Mode. Tap the Plus icon on the top right to add/remove application
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