Using WebP to compress raster map data.
Mapbox GL + WebP for iOS
A demonstration and source code on how to use Mapbox GL + WebP for iOS.
For the Cleveland National Forest map, "raster tiling with lossless PNG" created map data of 103 MB. "Raster tiling using WebP", covering the same region, and the same zoom level created map data of 34 MB. A reduction in size of 66 MB!!
Given that iOS Apps are capped at 100 MB... we at the Rob Labs are bullish on WebP.
See the source code at https://github.com/roblabs/mapbox-gl-native