Hi Jack- Unfortunately creating your own expense category isn't available in Crunch Free right now - the expense types are fixed, and match the general expense types that HMRC specify, but you're also able to add your own description to the expense for each item you add to help clarify exactly what you're claiming.
If the books are training/research books, they'd fit best under 'Staff Training'. You mention camera bits - if it's a battery pack that'd probably fit in 'Computer Consumable', and if it's some kind of film reel, then could use Printing, Postage & Stationery. Let us know if you need any further help!
