I fixed a minor bug in Field Ballistics. The new version is 184.108.40.206. It is available on the Windows Phone store now.
The bug was that under certain situations you could delete the last target. Other places in the app required that at least one target exist at all times. After deleting the last target the app would immediately crash.
As a side note: I submitted the changed version Sunday evening. It made it through Microsoft certification in less than three days.