Playing catchup in the Android smartphone market to Samsung and in some respects HTC, Korean electronics giant LG has today launched an updated version of its custom Android user interface — Optimus UI 3.0 — making it easier for handset owners to interact with their LG smartphones.

With HTC now offering version 4.0 of its Sense UI and Samsung recently overhauling TouchWiz to include a whole host of new features inside its new flagship handset, the Galaxy S III, LG has introduced new unlock functions, new Quick Memo functionality and voice interactions.

The Quick Memo feature built into Optimus UI 3.0 builds upon the recent trend of drawing and stylus applications, providing a way for handset owners to jot notes on their LG device using their finger. These sketches can then be shared on social networks, text messages and e-mails.

lg op32 520x338 LG debuts Optimus UI 3.0 to compete with HTC Sense and Samsung TouchWiz

Also coming with the release of Optimus UI 3.0 are new unlocking gestures, which can wake a smartphone by dragging anywhere on the screen. Users can also set the Pattern Lock feature to immediately launch a preset function (including launching the camera), as soon as it is unlocked.

Apps are sorted in order of their use and photos can now be set as icons and shortcut images. LG has included a new ‘Voice Shutter’ function that can snap photos using just your voice.

The new UI will be included on the LG Optimus LTE II launching this week in Korea, with the rest of the world getting it when they buy the LG Optimus 4X HD from June.