OpenTopoMap Viewer now supports direct offline tile ZIP import.

In the past, preloading tiles relied on copying files into shared storage so osmdroid could discover them automatically. Unfortunately this became increasingly unreliable on newer Android versions due to scoped storage restrictions. On top of that, osmdroid’s legacy preload/import functionality was left in a buggy state when the project was archived.

To solve this properly, OpenTopoMap Viewer now includes its own interactive offline tile importer.

You can now:

– open the new “Import offline tiles” option in the Cache settings
– select a ZIP file through Android’s built-in file picker
– import tiles directly into the app’s offline SQLite cache

No manual copying to `/sdcard/Download`, no special storage permissions, and no fragile preload workflow anymore.

The importer currently supports these ZIP layouts:

OpenTopoMap/{z}/{x}/{y}.png

and:

{z}/{x}/{y}.png

The imported tiles are available immediately, including in airplane mode.

Below is a short screen recording of the new feature in action.