You don't need an hour. Consistency beats duration.
: Features like re-closable rings for on-the-go learning or touch-and-feel textures can increase a toddler's engagement. ABC Flashcards for Toddlers
No educational tool is without critique. Detractors rightly warn against over-reliance on flashcards for several reasons. First, is a risk: learning letters on cards does not automatically transfer to noticing letters in environmental print (e.g., on a stop sign or cereal box). Second, reductionist learning —focusing solely on letter names—can overshadow the more critical skill of phonological awareness (playing with sounds in words). Third, flashcards are passive if used incorrectly; they should never replace rich language experiences like shared book reading, storytelling, or conversations. You don't need an hour
Toddlers are not known for their gentle touch. Paper-thin cards will be crumpled, torn, or chewed within minutes. Look for "thick cardstock," "laminated," or "coated" cards. Some brands even offer plastic or waterproof cards, which are excellent for bath time or messy play. No educational tool is without critique
Instead of holding the card, hide it. Say, "I spy with my little eye a letter that starts the word 'Balloon'." The toddler has to search the pile for 'B'. This teaches initial sounds, not just memorization.
Consider whether your toddler would benefit more from a tactile touch-and-feel set or an interactive talking reader to keep them engaged.