A new version just got published to the Market. Find it here.
Changes are to make it compatible again (for those with FUP products) with the T4T API changes of last weekend.
For FUP products, it will now show you your current total used volume, together with your min/max remaining volume, somewhat like this:
17GB (152/605)
Where 17GB is your used volume & the numbers in brackets are the min/max remaining volume respectively.
For more info on how to interpret the min/max remaining volume, I gladly refer to Telenet. :)
That's it!