@organicmaps great news, and I've already submitted some links to opendata DEM for Bulgaria.

I was wondering though, my cartography study books indicate that the digits on the isolines are to be always oriented uphill, especially in cases like @organicmaps where there's no hillshading or any way to figure out the direction of the slope. Maybe an enhancement for a future version?

Here's an example where the digits are upside down in the screenshot from your post: