Today TeX Writer update with the bluetooth keyboard fix is available. We have to apologize for the delay. Last time we tried, Apple wasn't ready to accept iOS 9 builds. Then we sort of took a nap, and when we woke up, it's already very late in the game. Thanks for bearing with the inconvenience during the wait.
A quick fix of iDOS2 is also on the way. But a more thorough fix will have to wait because the incompatibility issue is so tough that we have to spend more time on it.