Fluent word recognition is an essential component of skilled reading, yet most children with reading difficulty have impaired word recognition. We developed and evaluated a web app, WordDriver, delivered via teletherapy, which targets phonological recoding to support orthographic learning and efficient word recognition. Participants were five children (aged 7-10 years) who, despite previous intervention using a systematic, synthetic phonics approach, demonstrated persistent word recognition impairment. Two studies, each using a single case experimental design examined changes in decoding accuracy (study 1) and orthographic learning (study 2) as measured by researcher-developed nonword reading and spelling lists, and standardised nonword reading assessments. Results suggested that all participants, irrespective of oral language and phonological processing profiles, made significant gains in decoding accuracy and orthographic learning for targeted vowel digraphs on researcher-developed nonword reading assessments, with clinically significant gains on standardised measures of decoding, and trends for generalisation in spelling.