The first half of the ad showed three students getting hit by a car. In the second half, the app alerts them to the approaching vehicle and they jump out of the way just in time.
During the 30-second ad, a humourous voice over, feigning solemnity, explained the purpose of the app.
Lorna entered the competition last year and was shortlisted to the top 10.
"I decided to enter the competition again because I wanted to try and do better. I based the idea of the ad on my science fair project which I did on special effects.
"I would like to have a career working with editing and special effects so this competition is an ideal way to improve my skills and get to know different editing programmes.
"If I have a good idea next year I'll enter again and hopefully do even better."
Lorna said she hadn't expected to place and was overwhelmed when she was told her group placed third.
"They get hundreds of entries for this competition so I wasn't expecting to get a placing, but I was hopefull and then when I heard I was so excited."
Eleanor said she had heard about the competition from a friend and decided to give it a go.
"It sounded like it would be an interesting thing to do and I knew it would give me a really unique experience."
Eleanor said the whole project was worthwhile and the team had a lot of fun.
"We learnt a lot while we were making the ad and it was good fun. I would definitely be keen to enter the competition again next year."