The couple visited the community radio station Reprezent which trains youngsters in media skills.
Onlookers cheered as the couple arrived at the station, housed inside shipping containers in the diverse south London district, a hub for Britain's African and Caribbean communities.
Although the royal family does use social media in an official manner, none of the royals have their own personal social media accounts that we know of. Markle will join the foundation after she marries Harry.
Before they left, Meghan added: "I must tune in".
The bride's father, who has been divorced from Doria Ragland since Meghan was 6, has kept a low profile since the royal engagement was announced. Brand Finance's chief executive David Haigh recently said: "We think approximately £200 million will come from tourism, travel, and hotels".
When is Egypt not an African country?
Salah was then joint top-scorer in the final round of qualifiers as Egypt reached the World Cup for the first time since 1990. I had a fantastic time, especially with the national team where we qualified to the World Cup for the first time in 28 years.
Station founder Shane Carey said news of the visit had caused "massive excitement".
To make you feel better, here are a bunch of pics of Meghan and Prince Harry from today.
The Reprezent training programme, established 10 years ago in response to rising knife crime, helps young people develop and socialise through radio and has become a springboard for United Kingdom music talent, with former DJs and presenters working in the music industry.
St George's Hall is next to the chapel at Windsor Castle, but Frogmore was already said to be close to Meghan's heart because they had their engagement pictures taken there and she took Harry for a romantic picnic at the venue last summer.