Stop doing sums in the sun.

Anyone putting a tank mix together from label rates. Spot spraying or a full tank — knapsack or backpack, or a unit on the ute. Bush regeneration and environmental weed control, parks and gardens, landcare and volunteer groups, councils, and contract sprayers. Horticulturist, nursery worker, gardener? Yes, it works for you too. It isn't built around broadacre farming, though the arithmetic doesn't care.

The arithmetic is exact. The rates are a convenience, not gospel — verify them against the current label before you mix, since that's the document that actually governs. Not agronomic advice, just maths.

Add it yourself, once. It saves to your device and travels with any mix you share to a workmate.

Yes. The arithmetic doesn't care where you are, and any product you add yourself — with the rates you use it at — behaves the same anywhere. What's Australian is what ships in the box: the handful of built-in products, the label and SDS links against them, and the app's talk of the label as the legal document, which is written to Australian rules. Add your own once and that stops mattering. Metric only for now, so if you're in the US or Canada, imperial is on the way.

Yes. A rate can be a dilution ratio — 1:1.5, 1:50 — as well as a per-100L rate, a percentage, or a rate per hectare. Grams and millilitres both, so a dry product works the same way. That covers cut and paint (cut stump), drill and fill (stem injection), gel work, and other woody weed control methods.

It might be. Give it a boundary file or a plain number of hectares, and your litres per hectare, and it works back to the tank volume, how many full tanks the job takes and what goes in each one. It'll walk you through calibrating a knapsack or a hose and reel, though not a boom — no nozzle output at a given speed and width — and it keeps no spray records. On a smaller or mixed operation it may be all you were after. If it isn't, tell me what's missing — enough interest and agriculture gets built properly, either as a side to this app or as one of its own.

No. Nothing in the maths knows what's in the drum — it works on a rate, a volume and a container, and that is all. An insecticide, a fungicide, a wetting agent or a liquid fertiliser mixes exactly the same way: add the product with the rates you use it at, and the rest of the app carries on as normal. The name is what it was built around, not the limit of what it will do.

No. The app works fully without one. Sign in if you want your mixes backed up and synced across devices — worth doing, since data you never sync isn't guaranteed to stick around forever.

Not guaranteed — even without losing the device. Data that's never synced can be silently cleared by the OS after a while of not being used (iOS in particular does this). Losing or replacing the device has the same effect. Sign in once and none of that matters — it's backed up and just picks up on the next device. (This whole problem goes away once native Android and iOS apps arrive.)

Yes! Install it once and it runs with no signal at all — the maths happens on your device, not on a server.

Probably. And if the phone genuinely can't run it, the app says so in plain words rather than showing you a white screen and giving up.

Google or a one-time email code — no password to create or remember. Nothing personal is stored, your identity is kept as a hash, and you can delete your cloud backup yourself at any time.

Free while it's in beta. After beta? Probably a small purchase price to help cover running costs.

A few things: proper native apps for Android and iOS (no more relying on sync to avoid data loss), imperial units for anyone not on metric, and support for other languages.