I\'ve build an Android APP with offline map data using Openstreetmaps and OsmDroid. On a device with MDPI 320x480 pixels the map looks OK, but on a device with a HDPI screen
Osmdroid works with tiles that are static PNG images. You can not change the tile images. If you want to have a better mapping solution try MapsForge. This app/library works with maps data and renders them dynamically. This way you have more control on rendering maps and you can customize its texts and fonts and colors.