You can use iTunes to transfer these files to computer:
Step 1. Connect your iPhone your computer and launch iTunes if it doesn't run automatically.
Step 2. In the iTunes window, click the "Device" tab and select "File Sharing".
Step 3. Select the app shown in the list from which you want to transfer files to PC.
Step 4. Select the files you want to move to the computer and click "Save to".
Step 5. Select a location to save the items and click "Save to" to start transferring files from your iPhone to the computer.
However, it only supports a few apps. If you want to transfer more stuff from iPhone to your computer, you can use some third-party software like Leawo iTransfer. With this kind of software, you can directly drag and drop files to transfer between iPhone and computer. Anyway, here is a post including some recommended iPhone transfer software: 10 Best iPhone Transfer Software
