I am trying to make offline maps through caching (IndexedDB) in browser. I understand the concept is that I download and store the tiles of map first when connected to internet.
I have cache example implementation http://tbicr.github.com/OfflineMap/leaflet/index.html and code https://github.com/tbicr/OfflineMap/tree/master/leaflet_idb_sql_site.
For storage used IndexedDB and WebSQL. Storage had low performance and not tested.