Xero mobile phone app (available at the App Store or Google Play) enables you to have Xero with you anywhere anytime.
Reconcile your bank transactions anytime. Match your bank transactions from your phone in bed, over coffee, or on the bus and start your day knowing where you stand.
Capture expenses on the go. Record your expenses when you're out and about, and avoid lost receipts when you upload a photo on the mobile app.
Invoice while you're still on the job. Get paid faster by sending invoices as soon as the job is done, even when you're still on site.
Take your customer contact details with you. Always have your customer or supplier details on hand. Look up the address you're going to or find the phone number you need.
More information can be found here