Write an Android application

I am looking for an android phone app. The purpose of this app is to give me the gate key code when I am driving into to a community with gated access. I have a database of about 30,000 address records that would need to be geo-coded. This database also has the "KeyCode" for each address. What I need the app to do is read the GPS of the phone, and then display the nearest 10 "Keycodes" of the 10 nearest addresses to the current location. IT doesnt need to display the addresses, just the codes, and perhaps the distance away. Here are a few sample lines of the database that I have: 3150 SOFT BREEZES DR 89128,#4325 7813 RIVIERA BEACH DR 89128,KK2524 1628 BOUNDARY PEAK WAY 89135,#4300 3151 SOARING GULLS DR 89128, **3434 4751 CLOVER RIDGE ST 89147,#0942 3151 SOARING GULLS DR UT 1155 89128,#6512 1013 ELLIOT PARK AVENUE 89032,#9897 It is a simple app, I am hoping it should not be too hard. If the geo-coding of my database adds too much dificulity, I may be able to do it myself. But I would still need the rest of the app done. Thank You