tomtomtom123

Locus Maps switches the screen on when nearing a waypoint (turn) and then switches it off a set amount of time after the notification. You can set the distance before the waypoint when the notification activates, and the time that the screen remains on. For example, i think I have it set to notify 200m before a turn, and for the screen to remain on for 30 seconds. There is a hand waving feature where you wave your hand over the IR proximity sensor to turn the screen on for the same amount of time as the notification, but the IR sensor might be blocked if the transparent cover on your phone bag doesn't transmit IR. With the auto on/off screen function, Locus Maps uses 10% battery power for 1 hour of navigation time on my phone but this depends on how often there is a notification or manual activation of the screen, so theoretically if I use 90% of my battery power, I could get an average of 9 hours of battery life. There is a night mode which inverts the colors of the vector elements and uses dark colors.

You have to give the app superuser access in the security options in order to display over the lockscreen. This also lets you drag around the map without having to enter a password.

You can set the app to cache the map tiles that you browse, so that they're available offline. Or if you buy a region for a few dollars, it will save the region to memory. Alternatively there are people who have built custom maps from online sources of certain popular routes and made the package available for free to download, which you can unpack into locus maps. For example, there is a German guy who has created locus maps packages for all of the EuroVelo tracks.

If the maps are already saved to memory, you can simply switch on airplane mode to switch off radio signals except for bluetooth for the speed/cadence sensor, and this will save a lot of battery power.

I used to use Mobile Atlas Creator to cache and package map tiles of hiking routes to run on OruxMaps on Android. But a long time ago, a lot of the map sources, like openstreetmaps, banned mass download/ripping of tiles because of the large bandwidth required. I think that's why Locus Maps charges money to download map tiles because they get the copy of the map source from the owner, load it onto their own servers, and send you the tiles from their own servers when you buy the region.

Wahoo I believe caches the maps onto local memory with regular updates. I know that Lezyne requires you to have internet connection to download the openstreetmap tiles onto their devices. The problem with Lezyne is that you always need an internet connection to redownload the route and tiles everytime you power off and on the device, because the memory gets wiped once you turn it off. Bryton instead saves an entire region of openstreetmaps onto the device. In order to update the maps to the latest version, you have to use their PC software to update the firmware of the device. But All of these devices use a simplified version of openstreetmaps. If you use Locus Map, you can load different variations of openstreetmaps, like the cycling or hiking version (I believe they're all the same dataset, but with different parameters to render elements differently so that cycle paths or hiking tracks are more visible). The nice thing about Locus map is the ability to shade elevation, and draw contour lines. The curor can also display the altitude of the point at the cursor, so that you can estimate the elevation.

For backcountry routes of New Zealand, the NZ Land and whatever agency publishes free topographical maps of the entire country. They're also available online. It shows all huts, tracks, waterways, rope bridges, etc. It's the same as the paper maps that you buy at the Department of Conservation shops. With Mobile Atlas Creator, you can rip the online tiles and save it as a package to load into OruxMaps or Locus Map.

Map tiles come in different levels. I can't remember the unit scale of a level, but it might go from 1 to 20. At high levels, more geographical or manmade structures are rendered.
https://wiki.openstreetmap.org/wiki/Zoom_levels

If you use Bike computers like Wahoo, Lezyne, Bryton, you might get maybe up to tile level 13 or 14 of resolution, plus the streets. If you use OruxMaps or Locus map, you can cache maybe up to level 18 with buildings with address numbers and geographical features but would take a lot of memory. If you stick in a 65GB micro SD card in your smartphone, you won't have a problem with storage. I don't know the exact levels that the bike computers have, I'm just making an assumption based on memory limitations and the need to render on a black and white screen.

I switched to Locus map over from OruxMaps because Locus has more features that work well with a bicycle and sensors. It's also a little more easier to use (but still lots of option you have to learn what they do) and has more variety of available map sources and types, plus the route creation, navigation, and auto rerouting. I think it's got a bigger team working on it too.