Thunkable Live will not work now

I’ve been away for a few weeks, and now when I try to open Thunkable on an iPad, it simply opens and then shuts down. Has there been an upgrade whilst I’ve been away?

I’m not an apple person, so I don’t have an iTunes account and cannot remember where I got the Live app and how I installed it. Can someone point me in the right direction so I can re-download it and re-install it.