The first step is to redownload simPODD. You can redownload purchased apps for free. You can find instructions in the Redownload an App section of https://support.apple.com/en-u...

Once simPODD finishes redownloading open it and follow the prompts to create a new user. From here, you can try to restore a backup.

To look for and restore an automatic iCloud backup:

  1. Go to Options Menu Small, then Settings.
  2. Go to Backup.
  3. Tap Manage Backups.
  4. Find the file you want to restore in the list. You may need to scroll down. When you find the file, tap the ellipses Backup Small on the right, then tap Restore.
  5. Select the option to restore the backup to the current user.
  6. Wait for simPODD to finish restoring the backup.

Going forward, you can prevent apps from being deleted. For more information, see https://support.apple.com/en-u...