Receipt apps that sync to Xero usually cost a monthly subscription. If you just need your receipts in Xero, a CSV is enough.
Xero imports statement CSVs with Date, Amount, Payee and Description columns. The Pro license exports a Xero-ready layout; with the free CSV you map columns in the import screen.
Privacy: images never leave your device. Free: 5 receipts per batch. Pro ($19 lifetime): unlimited batches + QuickBooks/Xero CSV layouts.