Under the Recent tab, you can see the last 20 items, that you've uploaded. All you need to do is tap on the button in the top right corner of your home screen and this will open the Recent tab.
Every time you add an income invoice or an expense receipt, your upload will be visible in the Recent tab. Here you can also see all the items, which are currently being processed. If an invoice fails to upload, it will get a "failed to process" status. But don't worry, you can always delete it by tapping the "delete" icon.