Here is a set of flash cards with dotted letters for the phonemes of Phase Three. Laminate them for children to trace over with a dry wipe pen perhaps?
All Phase Three letters - flash cards - dotted - UK font - Log in or Become a Member to download
All Phase Three letters - flash cards - dotted - US font - Log in or Become a Member to download
Here is a zip file of all the suggested words for Phase Three (apart from the "tricky words") with "sound buttons" underneath which the children "press" as they read the phoneme above.
This is a huge bundle of word cards, printing 4 to a page, comprising all the suggested words in Phase Three, divided into batches of Set 6, Set 7, consonant graphemes, vowel graphemes and a combination of the Phase 3 graphemes..