Iphone-4, Use Dual sim
 

Just one Divice same lik cover

• 2Phone is compatible with iPhone 4 perfectly, it can make your iPhone 4 Dual SIM Dual Standy or Dual Mode Dual Standby.
• Two SIM cards online, no need to switch network, then you can enjoy calling, phone answering and message sending as you like.
• Dual SIM Dual Standy: GSM、3G(WCDMA)
• Dual Mode Dual Standby: GSM、CDMA

First Step: Jailbreak Please refer to tutorial: (click here)
Second step: Click cydia icon＞Manage＞Sources＞Edit＞Add＞input www.2phone.com/cydia＞Add sources＞Return to cydia＞Select 2phone＞Select www.2phone.com＞ Select 2phone ＞Install＞Confirm＞Restart device

How to update 2phone software (Connect with network via 3G or WIFI)
Click cydia icon＞Manage＞Sources＞Select www.2phone.com＞ Select 2phone ＞Modify＞update＞Confirm>Restart device

Thanks, for good information ...
aayushjaiswal