My name is Mo the creator of appicon.co I’m sure some of you have you used it once or twice. Source: over 1 year ago

You can use something like https://appicon.co to create them all from a 1024x1024 then drop the entire folder into your project. Source: over 1 year ago

App Icon Generator can be used for generating the images. Downloaded images should be stored in mipmap (android/app/src/main/res/mipmap-*hdpi/ic_launcher.png) folders. - Source: dev.to / over 1 year ago

There are a lot of icon generation websites like https://appicon.co you can restrict the size with constraints and set the content mode to aspect fit. Source: almost 2 years ago

Generate the pack of icons for Android and iOS here and unpack it. - Source: dev.to / almost 2 years ago

Https://apps.nextcloud.com/apps/phonetrack (if you have a nextcloud) The nextcloud one is by far the lightest on my phone battery, the other ones would often use very much battery. But I use android and YMMV. - Source: Hacker News / over 1 year ago

You mentioned a standalone solution rather than the Nextcloud option -- just to throw it out there, here's the nextcloud plugin: https://apps.nextcloud.com/apps/phonetrack. Source: over 1 year ago

Nextcloud Maps works quite well. You can even use the tracker app: https://apps.nextcloud.com/apps/phonetrack. Source: over 1 year ago

There's a Nextcloud plug-in that does this. Hopefully that's a somewhat useful start. Source: over 1 year ago

There is PhoneTrack as an app, not OwnTracks but it does have similar features and it worked for me in the past. Source: about 2 years ago