Words with Friends crashing, how can I avoid buying app *again* : )

Hi-

Just updated to 4 from 2nd generation. WWF wouldn't update after I finally got it on new phone.

There are no updates available on laptop or phone

Now it's crashing

Guessing I'll have to re-download. Is this correct?

And if so, how can I avoid paying $2.99 again?

Thank u!