The duo were seeded ninth but defeated the Beijing Olympic bronze medallists en route to the semi-finals. They lost 21-19 21-18 to Brazilian duo Vivian and Lima in the bronze play-off. Johns said: "It's the best we've played probably ever. Finishing with a loss is disappointing but we're happy overall."
A capacity crowd of 1,500 watched the bronze-medal match at Horse Guards Parade on Sunday, with 15,000 supporters expected to attend the Olympic event next year. "The crowd have been great and the support has been really inspiring," Boulton told BBC Sport.
"We've enjoyed the competition and have really risen to the occasion because this was a chance to showcase our sport - I'm so happy that we were able to perform well.""The atmosphere was absolutely amazing - to think what it could be like in a year's time is incredible and it make us just want to train and work harder and get some good results to ensure we make it to London."
Johns and Boulton are ranked 51st in the global standings, behind fellow Britons Shauna Mullin and Zara Dampney, who are 32nd. Although it is possible for two GB teams to qualify for the Olympics, realistically the two pairs are battling it out to take the one guaranteed position that Great Britain are entitled to as the host.
"We still want to get two teams in, but if not we just have to do everything we can to make sure we've got the results that we need to qualify," added Boulton. Dampney and Mullin won all of their group matches and defeated Spain in the first knock-out round, but came unstuck against eventual winners Lili and Vieira from Brazil.
Dampney said: "It's been an amazing week, we've played our hearts out on the court and we just wanted to show everyone what beach volleyball is all about. It's been the highlight of our season and so much fun."
Beach volleyball provided quite a contrast to the widespread riots London experienced during the first few days of the competition. The event itself remained relatively unaffected, with only a few matches brought forward on Tuesday evening to allow spectators to return home early.
"We've proved to the world that despite the incidents earlier in the week, which none of us are happy about, all of the test events coped well and it's an opportunity to learn from that experience," said British Olympic Association (BOA) chief executive Andy Hunt.
Hunt was so impressed with the beach volleyball event that he suggested there should be annual competitions at Horse Guards Parade. "I think it's been absolutely brilliant," Hunt told BBC Sport. "There can't be a better backdrop for the sport and I'm sure it'll be a perfect setting for beach volleyball come the Olympics."
Both British pairs will now travel to Finland to compete in the next FIVB World Tour event, where they will hope to build on their strong performances in London and continue their push up the world rankings.