I use the software on my laptop, I don't have the latest version because, like KGarrad I don't connect to Ancestry, I choose not have a tree on there.
I have the app on my iPad for the convenience of having my complete tree to refer to when out. The disadvantage of the app you, can't edit it, so if needed, I make notes to add information to my tree on the laptop and regularly transfer the updated version to the iPad.
I keep several trees on the app, this is convenient for showing computerless friends what progress I make on their trees.
I also carry RootsMagic on a memory stick, this I can plug into any computer and edit my tree, or share sections with relatives.