Although it is important for children to know the consonant and vowel sounds associated with single letter phonograms, it is equally important that children grow in their knowledge of the sounds of phonograms represented by multiple letters. Knowing the most common sounds of letter combinations expands children’s abilities to decode new words. The Pihana Letter Combinations app builds on skills targeted in our first mobile app, Pihana ABCs, toward the development of more advanced phonological skills focusing on associations between commonly encountered blends, digraphs, and diphthongs, including the sounds they represent. This app is designed to teach each set of letter combinations through a series of interactive activities that increase in complexity as the child progresses in ability. This app is designed to teach high-frequency letter combinations through a series of interactive activities that increase in complexity as the child progresses in ability. Of the 28 featured letter combinations, the majority represent one sound in more than half the words in which they appear. The app offers three scaffolded modules comprising fun and engaging activities designed to accommodate children working independently or under the guidance of an adult. All activities are programmed to provide immediate graphic and audio feedback that reinforces learning and incentivizes engagement through multi-modal functions. One of the modules includes a handwriting practice activity that features all 28 letter combinations in a format that reinforces children’s letter recognition and fine motor skills by allowing them to trace the individual letters. All three of the modules will help parents and teachers assess the extent to which the featured letter combination are in a child’s store of knowledge.