Geo Data Collector supports Raster Map Tiles in MBTILES and GPKG SQLite offline databases
If you’ve got GeoPDF/Geospatial PDF, MrSID, JP2, GeoTIFF, ECW, IMG other Raster Formats you want to show please create map tiles. QGIS Desktop or GDAL_Translate or GDAL2TILES.py and python script for packing. Or Commercial software like Manifold and Global Mapper and MapTiler.
If you are an ESRI user there are python scripts to convert ESRI Proprietary Tile Package formats (TPK and TPKX) to MBTILES or GPKG.