@prog-amateur - welcome to TMO!

Good questions, let me reply:

1. Yes, version for L5 and Sailfish OS are both developed. This goes for Pure Maps and OSM Scout Server. I am planning to support the both platforms when L5 will get out and, with the current implementation, it should be easy (kind of easy) to add other QML platforms. By supporting more platforms, hope is to get more developers and pro-active users on board and get help with the work on this solution.

2. HERE Maps is competing with Google. So, they have made an attractive offer for developers to get as many of them to work on their platform. As a result, we can get rather large allowance of free downloaded tiles from them. We could expand it to routing and search as well, but it may require further compartmentalization of HERE into separate profile for legal reasons.

3. Not yet. You can buy any phone or tablet supported by Sailfish and install Pure Maps on it. Or any Linux device that you may consider as a GPS device. I wonder if RPi with touchscreen and GPS would do the trick.

As for traffic or location data, your location info is not transmitted from Pure Maps to the used services. Traffic is provided by HERE via their raster map tiles; Mapbox also gives the data as a part of their datasets. We are so far operating within free limits, that we hit once in a while. For Mapbox data, users are encouraged to register their own access codes.

When using online services, you do request map tiles, perform search or routing request on their server. So, in theory, some data can be processed regarding you. Although, it has to be tracked by your IP address, if possible. Providers usually have legal description of what can they do with it, if anything, and you can consult it too.

Finally, Pure Maps sits on top of Qt. So, if Qt is compromised and sends the data somewhere regarding your location, this cannot be avoided by Pure Maps. Although, I have never heard about such incidents and it would correspond to the compromised device - something that applications running on top of the OS cannot do much about.