The order book has survived for decades because it is fast and never crashes. Any app that replaces it has to clear a high bar: it must be quicker than a pen, work without signal, and be learnable in five minutes. Most fail on at least one of these.
Speed is the only feature that matters
A salesman makes 30-40 calls a day. If each order takes two extra minutes, that is over an hour lost — and he will resent the app. The target is 90 seconds per order: pick the shop, tap products, set quantities, place. Recent shops and fast-movers should float to the top automatically.

It has to work on a weak network
Markets have basement shops and dead zones. An app that freezes on 2G is useless. Order-taking should feel instant regardless of signal, syncing quietly when the connection returns.
Give the owner the view, the salesman the beat
Each salesman should see only his own route and shops — less clutter, faster work. The owner sees every route's orders, value and coverage in one place. Now 'how did the market do today?' has an answer by evening, not next week.
Roll out with your best salesman first
Pick the salesman who is respected by the others and put him on the app first. When the team sees their toughest colleague finishing his beat faster, the rest follow without a training session.

