I use geohunter on my android phone because it seems a lot quicker than the other apps i've tried at dealing with large databases, the others taking ages to load cache lists, i normally have whole areas on my phone because i travel around a lot (2000+)mainly caches along a route so no matter where i decide to stop and cache i keep data usage to a min. You can also use offline Ordnance survey mapping (via Rmaps)with caches shown on map which is fantastic. I sync my PQ's with Bcaching.com via Auto email address and then sync phone with Bcaching once a week via wlan at home which gives me all updated logs , finds etc
