MACSWEEP  As far as I can tell, this application is missing all zip codes in Alaska.  
(Version 1.0.1)

MACSWEEP  This is very handy to App and best of all it's free.

Usually very accurate. However, there are numerous zip codes that are not listed, some of which are Wesley and Lowell, Maine and of the 3 Oakwoods in Ohio, only 1 is listed by FourOneOne.

It would be even better if the user could reverse look-up. That is, input a code and have the proper information come up.  
(Version 1.0.1)

DRZOOM  los angeles, ca missed the 310as area code for the phone

"The 310"

Area code 310 covers most of West Los Angeles and is commonly synonymous with it: young people often refer to the region as "the 310." Ironically, area code 310 also covers some of the lower income communities in the Los Angeles area, such as Gardena and Compton. In April 2005, local telecommunications providers petitioned the California Public Utilities Commission to overlay area code 424 onto 310, due to a projected shortfall of telephone numbers; this overlay will be in use beginning in August 2006.

santa monica, Ca never used 562 as a area code for phone ( Santa Monica, LAX Airport, San Pedro, Torrance (part of Los Angeles County); (310/424 overlay in 2006)  
(Version 1.0.1)