Google has been working hard to encourage device manufacturers to have dedicated Google Assistant buttons on their handsets and says 100 million devices will launch with the feature this year. 

Google is talking about the button programme - first announced last year - at Mobile World Congress and it plans to roll it out to even more Android devices during 2019. 

LG and Nokia are bringing the button to all their new Android devices including the LG G8 ThinQ and K40 and the Nokia 3.2 and 4.2.

Xiaomi's new phones will also have the button including the Mi Mix 3 5G and Mi 9, while Google says that TCL and Vivo (V15 Pro) will also launch with the Google Assistant button later this year.

The button works in much the same way as a long press on the home button does currently on most Android devices. A single tap of the button will launch the Google Assistant and get it to listen to what you want it to do. A double tap essentially shows you Google Now-style information - a curated view with personalised and helpful information based on the time of day, location and your recent interactions with the Assistant.

Long-pressing the button activates a walkie talkie feature, so you can make sure the Assistant will listen to your full query - this is most useful for dictating emails or long text messages.

Naturally, the Google Assistant can perform various actions such as getting answers to questions, viewing your calendar, finding directions to the nearest coffee shop, starting music/podcasts, and control smart home devices with your voice.