What's the Limitation on Free Trial Version?
You're able to detect both phones to check the device connection in the free trial version. To transfer phone data to another phone, you have to buy a license and use the paid version.
For WhatsApp Transfer, it's available to back up smartphones' social app data in the free trial version. It will prompt Buy window if you start to restore the chats to a phone, or use the function of WhatsApp Transfer from phone to phone.
The Backup feature on MobileTrans is free even if you do not buy a license. You'll enjoy the backup function once you try it.
On the product Restore free trial version, you'll see the files quantity for every file category in the MobileTrans/iTunes backup files. If you'd like to restore data to other phones, buy a license and register it to restore.