The flmlfm app is organized like a set of card decks. Each deck corresponds to a tag (e.g. a community hashtag) or a collection of submissions for a particular challenge. Each card is either a challenge card, or a submission card.
As the user swipes through the cards
See How flmflm ensures voting is fair
For a detailed example see The Challenge Lifecycle
A challenge card should explain the objective of the challenge and any requirements. For example, the objective could be to juggle the most fruits at once for 60 seconds, and a requirement could be that the submission video must be a single take (no editing multiple shots together). You may explain your challenge in brief text form pasted over a cover image, or you may explain and/or demonstrate it in a video.
The submission card is a video you upload documenting your attempt to meet the challenge objective. At the least it should show evidence of your best attempt to meet the objective and requirements of the challenge. You are free to style and edit it as you please to impress the audience.