I created (draft of) an app for O-map symbols.
You can download it here: http://o-quiz.orienteering.info/o-quiz.apk
I don't have resources to work further on it on a larger scale, so I open sourced it: https://github.com/OrienteeringIsFun/O-Quiz
You can contribute by:
* uploading nice images of objects to https://pixabay.com
or similar pages and sending a link to me
* improve the code quality
* translate O-symbols names to your language: https://github.com/OrienteeringIsFun/O-Quiz/blob/m...
I hope you like this initiative.