Restore Purchases asks Apple to verify purchases already made with the current Apple ID; it does not charge you again.

Go Guide app

In the app

  1. Make sure the iPhone uses the Apple ID that originally purchased Premium.
  2. Sign into the correct Go Guide account.
  3. Tap Profile, tap the cog, then select Restore Purchases.
  4. Keep the app open until Apple finishes checking the purchase.
goguide.co.uk

On the web

  1. Purchases cannot be restored from the website because Apple owns the transaction.
  2. Restore in the iPhone app, then reload the website while signed into the same Go Guide account.