Kid Play

Watch the video here http://youtu.be/4DPK9XHIocM
As @ronxo explains a locked down launcher. You can go to the home screen but if you try to launch an application I do block it. So your child will not be able to launch an application even answer your text message either.

Lend your phone to others with allowing only approved applications to be used. Kid Play allows your children to select and play any application you deem
appropriate by putting your approved applications in
the Kid Play list . This application acts as
a Parental Control/General Control in allowing a filtering of applications that can be
used by the child or just your friends.
The reason I created this application was that I have given
my phone to the kids and 2 minutes later I received a call saying that everyone in the company received a gibberish email. Therefore,
I wanted a way to select only a small set of games
and applications for the children to play: like their favorite Angry
Birds.
The simple interface allows you to select the applications you
already have on your phone and allow only those applications to be
used by your kids or friends. It also stops them from going to
advertisement pages from inside the games that have mobile
advertisement in them.

Even though Kid Play is a filter that allows you to select the applications, I would still recommend you supervise the usage of your phone.Disclaimer Kid Play is not to be used to protect your phone from hackers or mischievous
people but only to keep users from wandering into unwanted
applications. I go by the motto that where there is a will there is a way and
will not let them investigate how too. It allows the stop of the
application when you reboot the phone which allows you to recover if
you ever forget your password etc.. The home button can not be
disabled therefore if the home button is clicked the application will allow access to the homepage but still protects by not allowing an application to be launched and within seconds of the homepage displaying Kid Play closes the homepage and redisplays itself. This application does not require a website or log in to a website. You only need to select the applications you already have installed for use.

After Install:
Step One: Click "Add Application" button. Select the application you will allow others to use.
Optional Step: Click "Manage Passcode" type in old password like 1 and type in your new numeric password
Step Two: Click Start. This will show a screen with a list of applications you have selected.
Step Three: Click the menu button to display the stop prompt type in your numeric password and the application will quit.
Optional Step: Click "Remove Application" button. This will display a list of applications you have selected. Click on one of the applications and it will now be removed from you approved list.

I hope KidPlay can meet your needs and allow you to give your phone to your kids so they can enjoy the games you have downloaded for them but not your email. Thank you for choosing KidPlay.