Try the app the way you actually work: on the phone, in a hurry, with a name you already know. You want a credit sale in a few seconds, two buttons that mean they owe you or you owe them, more than one currency, and a statement you can send to one person — not the whole shop.
If the demo starts with invoices and product codes, it is not this job. Kaymn’s trial is seven days and does not ask for a card. Start from how much they owe.