Some advices

Customers want to have a faster access to the recording. It can be done by using the CoreTelephony notifications in order to get phone call status changes.

Also you can use the AudioUnit Framework for recording without using 3d line connections.

For the reason of security you should store the audio records on users device. And take a payment for recording and not for listening record.

Accet about Call Recorder Lite for iPhone, v1.4.3