I wouldn't have thought that there is any specific software for the Windows phone on Ubuntu or any other Linux distro.
What is it that you want to do with it?
If you just want to transfer files to/from your phone, have you tried plugging it in via USB?
With most phones, the Ubuntu operating system would typically recognise a phone as an external device and auto-mount the phones SD Card as an external storage device and allow you to transfer the files using a file manager like Nautilus or Dolphin.
I've never owned a Windows phone, so I don't know for sure what happens when you plug one into a linux PC! With Android phones, you plug the phone into your computer via USB and select an option on the phone to allow the connection to the computer before you can access the contents of the phones SD card. And moving files to/from an android phone is extremely simple.
What happens if you plug the phone into your laptop with the file-manager open? Is there any sign from the OS that a device has been connected? Likewise, is there any sign on the phone that it recognises that it's been connected to a computer?
Using a quick bit of google-fu I've also found this which might be of some help! It seems it is possible to connect your phone to your Ubuntu PC, but there are problems when copying certain file-types to the phone. Also the author of the page is using a 920, but I'd guess that a 720 would be more or less the same! The page in the link is the third page in a Linux users review of the 920.
Windows Phone 8 OS will attach via USB to a Linux system and appear as a USB drive, allowing you to copy files from one to the other without problems. If it is an older Windows phone (7.5 or earlier), then it requires a Windows OS to connect with. As I recall, the 720 is a version 8 operating system, so it should not be a problem in getting photos from the phone to your Ubuntu system.
Linux is so smart. It treats phones as a usb flash drive and mount automatically and show all files and folders of phone. If it does't show files automatically, you can find your phone drive at /media folder as a external drive . I am usinng ubuntu from long time and I did't faced any problem till today to accessing phone device. The only problem I have faced with android phones. It store all files in phone's trash folder if you try to delete files of phone.