This week in apps features Brain Quest, the educational adventure series. Also this week is Elmo's Big Birthday Bash!, an interactive story from the Sesame Street gang. Pip and Posy allows preschoolers to paint and play counting games, while Old MacDonald Had a Farm brings the classic song to apps with 11 featured animals. Finally, Builda the Re-Bicycler tells a story of recycling on an island where everyone rides bikes.

Title: Brain Quest

Publisher: Workman

Release date: April 26, 2012

Price: Free

Background: Players hone their math, science, language, and history skills by going on an adventure with Casey, Jake, and Gizmo through the wisdom islands, snowy mountain passes, and outer space.

Features: Track scores for up to three players, review material changes to allow for multiple play throughs, content reflects national and state curriculum standarrds.

Title: Elmo's Big Birthday Bash!

Publisher: Random House

Release date: April 21, 2012

Price: $3.99

Background: 30-page interactive birthday story includes helpful reading tools and three games to practice early reading skills. Narrated by Bob from Sesame Street

Features: Record your own voice, read along, or auto play modes; parent tips.

Title: Pip and Posy: Fun and Games

Publisher: Nosy Crow

Release date: April 6, 2012

Price: $0.99

Background: Play games with Pip and Posy, the friends from Axel Scheffler's picture book series about the dramas of toddler life.

Features: Designed for preschoolers, the app allows players to use their finger as a paintbrush and color in scenes from the books, tap the screen to complete jigsaw puzzles, flip cards to find all the matching pairs in sets of 8, 16, and 24 cards.

Title: Old MacDonald Had a Farm

Publisher: Bacciz

Release date: April 18, 2012

Price: Free

Background: The classic tale includes 60 interactive animations, physics simulations, customizable options, professional vocal and banjo accompaniment, and facts about 11 farm animals.

Features: Each page is dedicated to one animal with its own verse in the song, highlighted text allows players to follow lyrics of the song.

Title: Builda the Re-Bicycler

Publisher: Midlandia Press

Release date: April 20, 2012

Price: $1.99

Background: The island of Midlandia is bicycle-crazy--but a problem seems to be piling up. When the town dump overflows with discarded bikes, Builda the factory owner springs into action. Her plan to reduce, reuse, and recycle just might save the day.

Features: Read to me, read to myself, and auto play modes. Narration by the author, pages pan and zoom to guide the eye and accentuate the story.