Can you use tags when snap receipts in the app? I can't see that it has that field, I have to snap receipt, create expense in the app then log into desktop to tag it?

Hello and welcome to the Community, info-smartstaysg

At the moment, tags are only able to be assigned at a transaction level to invoices, expenses, and bills. This means you'd have to review your receipt to create the receipt, and then tag. 

For further info on tagging transactions in QuickBooks Online, see here. We'll be here if you have further questions or if you require additional assistance.