There could be multiple reasons for the app disappearing from the iPod / iPhone / iPad. If the setup was done correctly, this should not have happened. Here are a couple of suggestions you should try out to fix this.
1. As a first step, try this. Connect the iPod / iPhone / iPad to the computer, launch iTunes and select the device from the left hand panel. Select the Applications tab and look for Mobicip on the list. If the checkbox for Mobicip is unchecked, go ahead and check it and click Sync at the bottom of the screen. This would install the app onto the device.
2. If you purchased Mobicip's Safe Browser app using your iTunes account on the App Store, and if your son /daughter has his / her own iTunes library, then the app could disappear upon sync'ing. Here is what you need to do if this is the case.
i. Launch iTunes on your daughter's computer.
ii. If she is logged in using her iTunes account, click Sign Out at the top right.
iii. Click Sign In at the top right. Login using your iTunes account. Some prompts may pop up asking you if you want to authorize the computer to use your iTunes account. Accept these prompts.
iv. Once signed in, search for Mobicip, and click BUY NOW. You will see a message that you will not be charged for the purchase. The app will be downloaded to the iTunes library on the computer.
v. Sync the iPod with the iTunes library. Mobicip's Safe Browser should now be installed once the sync is complete.
vi. Launch Mobicip and login using your Mobicip.com account.
There are a couple of other scenarios, but we don't need to go there until you try these out.