I already have a Demo (FXCM) Trading Station account and the software.
Problem is I want to download a[B][I] Pivot Point app[/I][/B], but it asks me
to log in to the main FXCM website, but I don’t appear to have
an ID or Password (other than for the MT4 software).
I don’t intend to sign any contract or agreement with brokers until I feel confident enough.
That’s perfectly understandable. 
You don’t have to be an FXCM client to use the custom indicators available in the FXCM Apps Store. (Though only FXCM clients can purchase automated strategy apps.) Simply register for a free FXCM Apps Store login.
Then you can download the Pivot Points app. However, if we’re thinking of the same one, then you will need an MT4 demo account.
Your MT4 login details will also work on our Trading Station platform which you already downloaded.
Welcome to the forum!