Once you've purchased OnSong, you should be able to download and install updates without issue. Here are some reasons that this may not be possible:
- You may have downloaded OnSong onto the iOS device using an Apple ID that is different from the one you are currently using. You may need to switch your iOS device to the other Apple ID prior to performing the update. It's recommended that you purchase apps on a single Apple ID to avoid issues with updates.
- Starting in 2013, Apple changed their policy regarding refunds. If you've asked for a refund on the purchase of an app, you will not be able to install updates to the app. If you've asked for a refund and wish to continue to receive updates, you will need to purchase the app again.
- There may be an issue on your Apple ID account that is preventing your from receiving updates. In that case, you would need to contact Apple Support to receive help. App developers do not have any means to assist you with purchases, downloads, installations, updates, refunds, or Apple ID issues since they are managed solely by Apple.
- You may be using a very old version of OnSong released prior to 2012 that is not upgradeable. You can check the version of OnSong and see if you are running OnSong 1.92 or earlier. In this case, you will need to purchase the latest version of OnSong for future support.