Naming apps or books

[Excitingtimesahead]

Can anyone suggest a good app or book to start the process of finding a short list for dc number 2.

A classic, accurate, reliable, reference book is
P Hanks, K Hardcastle and F Hodges, A Dictionary of First Names (2nd edition), Oxford University Press 2006.
You can consult it online here www.oxfordreference.com/view/10.1093/acref/9780198610601.001.0001/acref-9780198610601

or buy secondhand copies very, very cheaply from Amazon and other sellers:
www.amazon.co.uk/Dictionary-First-Oxford-Paperback-Reference/dp/0198610602

Thank you