Triptico is fantastic for IWB resources and learning 'widgets'
check out Triptico word magnets (this resource is being phased out in favour of a better paid-for version). Wait for the old site to load after the message about the new one. Screenshot here:
also Triptico draft it Here's an idea for using this resource:
Pupil 1 writes a sentence & clicks Save; Pupil 2 writes it again, correcting it or extending it, clicks Save; Pupil 3 writes it again, corrects or expands then clicks Save.You can then review this with the class