Additional instructions for the Android app

You can purchase the app install from the Play Store For the price of a cup of coffee you get convenience and support Karttahimmeli's development.

Updating

The Play Store app updates automatically, unless you have disabled automatic updates. Please check your settings.

Karttahimmeli's web app part updates automatically from the app on startup. Note: the app must be closed/killed for the web app update to happen. If you only leave the app with, for example, the back or home button, Karttahimmeli does not die. To be sure you get the latest web app version, it's worth closing it twice: start Karttahimmeli App, close it, open again, close and open once more.

Sending location to the operation

The app enables location sharing even while the screen is off. With a good GPS signal, location is sent about every 10s. With a poor GPS signal, positioning happens about once a minute. While stationary, location sending is throttled to about once a minute.

If the network connection has temporary problems, locations left in the queue are sent along with the next successful location transmission. The tail and the dot on the map only update once location sending has succeeded. So you see the same situation as everyone else. If your own dot doesn't move, others don't see it moving either.

While location sharing is on, the app shows a notification displaying the team name, the time of the latest location send attempt, and the estimated positioning accuracy. Location sharing does not stop even if you close the app — it must be switched off from within the app.

Background location sharing works for a maximum of four hours after the map was last viewed. The assumption is that the map is glanced at every now and then, so the four-hour limit should not normally come up in practice, but it prevents location sharing from being left on for several days after the operation is over, unnoticed.

By checking the latest positioning time in the notification, you can tell whether background location sharing is working or not. This does not, however, tell you whether the location was also sent to the server.

Installation and required permissions

Karttahimmeli only asks for each permission when it's actually needed. Approve the requests as described below so that location sharing also works in the background.

Prerequisites

Karttahimmeli installed from the Play Store.

1. Open Karttahimmeli for the first time. When the OS asks for the location permission, choose "Allow only while using the app" (or equivalent) first — this is enough to show your own location on the map.
2. When you start sharing location for a team, Android asks for the location permission again. This time choose "Allow all the time" — only this allows location to be shared while the screen is off.
3. Also approve the notification permission if the OS asks for it separately. The notification shows the status of location sharing the whole time it is on.

Outcome

Karttahimmeli can share location in the background with the screen off, and a notification showing the sharing status appears while it's active.

Both location prompts at once

Some phones show the "while using the app" and "all the time" options in a single prompt already on first launch. In that case, choose "Allow all the time" directly.

Battery and permission settings

Background location sharing can stop for two reasons: the phone's power-saving mode is restricting the app's network and GPS use, or the OS has removed the app's permissions on its own after a period of disuse. Both settings are found under Settings → Apps → Karttahimmeli (the exact path and wording vary by manufacturer and Android version).

Remove permissions if app isn't used — turn this OFF

By default, Android now removes an unused app's permissions (such as location) after a few months of inactivity. This is especially risky for a search app that's used infrequently: months can easily pass between operations, and when the next alert comes in, location sharing may have silently stopped because the permission is gone.

Find the "Remove permissions if app isn't used" switch in the app's Permissions screen and turn it off.

• Battery: choose "Unrestricted" / "No restrictions" instead of "Optimised" or any other restricted setting.
• Permissions → Location: check that it's still set to "Allow all the time" — the OS can sometimes reset this back to "while using the app", for example after a major update.
• Sync (email, backups): worth turning off for the duration of the operation, to save battery.
• It's also worth turning screen brightness down to minimum manually.

Auto-brightness uses a lot of power outdoors

Don't use auto-brightness during an operation. Bright sunlight forces auto-brightness to its maximum, which drains the battery at almost twice the rate compared to a manual minimum level. Also when moving in the dark with a headlamp, a manual minimum brightness is plenty and saves significant battery.

Note! On some phones, GPS use starts being restricted once battery drops below 15%. This may show up as reduced positioning accuracy. It's good to carry a power bank.

The exact menu paths and wording vary by phone manufacturer and Android version. dontkillmyapp.com keeps up-to-date instructions for most popular phone brands.