At 20:00 BST on Thursday, households across the UK stood on their doorsteps and balconies and applauded the efforts of the NHS and care workers in treating those affected by Covid-19.
The initiative was devised by Annemarie Plas, from Brixton, south-west London, who was inspired by same event happening in her home country of the Netherlands, and in many other countries.
Annemarie posted details of the event on her social media channels, and enthusiasm for taking part quickly spread across the UK.
"I hope that it creates a positive boost for those on the frontline," she said.
"But also [when] you hear your neighbours applauding you know that we are together in this, because we are currently all in our houses."
Buildings around the UK were also lit in blue - the colour of the NHS logo - to pay tribute to the work of NHS staff, including Wembley Stadium, Belfast City Hall and Blackpool Tower which featured a blue heart.