UK Postcode Lookup is a free Android app developed by 3X software. It allows users to search for UK Royal Mail Postal Addresses based on postcodes. The app provides the postal address along with its location displayed on a Google map. Users can easily add the address to their clipboard or share it with others.

To use the app, users are provided with 5 free lookups per day. For additional lookups, users can purchase more credits from the postcodes4u website and obtain a key. After purchasing credits, users need to go to their account page to get the name of their key and enable it for mobile devices. The key, along with the user's email and postcodes4u password, can be entered in the app settings.

It is important to note that the app requires an internet connection to access the web service for address lookup. Currently, the only way to purchase more lookup credits is through the postcodes4u website. However, the upcoming version (V3) of the app will include the ability to purchase credits within the app.

For any suggestions or requests for added functionality, users can email the developer directly.