Most invoice delay is an approver who is not at a desk, so moving approval to a phone genuinely helps. It also introduces a specific risk that is easy to design out and easy to ignore: a small screen encourages a summary, a summary encourages approval without context, and approval without context is not a control. The useful version shows the document, not just the number.
What the screen has to show
The supplier, the amount, what it is for, the purchase order if there is one, and the invoice itself. An approver who can see only a reference and a total is confirming that a number exists, which is a different act from authorising an expenditure. The best approval screens make the document one tap away and show the match result plainly.
What it should make easy besides approving
Rejecting with a reason, querying, and forwarding to somebody better placed to judge. If approving is one tap and everything else is difficult, the software has an obvious bias, and the results will show it. A reject path that requires a reason is worth more than any number of approval features.
Notifications that respect people
An app that notifies constantly gets muted, and a muted app is slower than email. Batch notifications, escalate only when something is genuinely ageing, and let the approver choose a rhythm. The measure of success is elapsed time to decision, not how quickly the first notification was delivered.
Questions people ask about invoice approval app
Is mobile approval secure enough?
The security question is authentication and device control, both of which are standard. The bigger risk is approving without seeing the document, which is a design choice rather than a security one.
Should approvers be able to approve in bulk?
Sparingly, and never for anything that failed the match. Bulk approval of clean matched invoices is reasonable; bulk approval of exceptions defeats the purpose.
What if an approver has no phone?
Keep a browser path. An app should be an additional route to the same record, not the only one.