ANDROID APP

We are looking for Android OS developer how can help us to disable features of Cheap Samsung phone OS (Android). We want to let Cheap Samsung phone to only send SMS to specified Number ( Our Company Number ) , so our agent send SMS (Activation SMS) to our company, in general we are looking to: 1- Disable Sender field in SMS, so we only write SMS in Text field and press Send and message send to number we set in. 2- Protect phone from getting re-set to default. Note: I don't need to create SMS app, I need to work out the Android OS for SMS feature. Please if you require more details please be free to contact us. Thank you