A few weeks ago my wife added three things to our list while I was already in the shop. The notification arrived on my phone. I tapped it, the list opened, and the three things were not there. That one turned out to be my home Wi-Fi quietly blocking the app's connection while letting the notification through. But while I was digging through the server logs to prove it, I found something I liked a lot less: about one in ten people who signed up in September had never received a single notification from Listo. Not late. Never.
How a notification finds your phone
When you share a list, Listo does not send the notification itself. It hands a short message to Google or Apple, and they deliver it to your phone. For that to work, your phone has to ask them for a delivery address once, the first time the app opens, and tell Listo's server what it is. Think of it as registering a letterbox.
The asking can fail. On an iPhone the app sometimes asks a fraction of a second before Apple is ready to answer. Some Android phones ship without Google's services, so there is nobody to ask. And a slow or blocked network at first launch fails the way any network call does. None of that is unusual. What was unusual, and entirely my doing, is what happened next: nothing. The app stored no address, and it never asked again. Every later notification for that person reached my server, found no letterbox, and was thrown away with a one-line log entry.
What changed in the latest update
Three things, all on the phone, none on the server.
- Listo asks again. If the first attempt fails, the app retries a few times in the first minutes, once more each time you come back to it, and again right after you sign in. On iPhone it now waits for Apple to be ready before asking at all.
- Listo tells you. While it keeps failing, Settings → Preferences shows a short note under the notifications switch with the reason in plain words, and a Fix it button that tries again while you watch. If the real problem is that notifications are turned off for Listo in your phone's settings, the button becomes Open settings and takes you straight there.
- Listo remembers why. The reason for a failed attempt now goes into the app's own diagnostics on your phone, the ones you can share with me from the About page if something stays broken. It still goes nowhere unless you send it.
One honest limit: a phone without Google's services cannot receive these notifications at all, and no button changes that. The note in Settings says so instead of pretending to try.
If you think this was you
- Update Listo and open it once. For most people that is the whole fix; the retry happens on its own.
- Open Settings → Preferences. If there is no note under the notifications switch, you are set.
- If there is a note, read the reason and tap Fix it (or Open settings). A short message confirms when it worked.
- Ask whoever you share a list with to add something. It should arrive within a few seconds.
I would rather have written this post about a new feature. But a shared list only works when the other person finds out, and one in ten is not a rounding error. If your notifications still do not arrive after this, please tell me at support@rolisto.com. Half of Listo's best behavior started as one of those mails, and the other half started in the logs.
— Andrei