Well after some research and troubleshooting, I finally got the Sunbrite app re-installed!!!
Turns out that even though I had jailbroken my iPod Touch, I needed to install something called 'Appsync' to allow .IPA files to be installed, which is why I was having so much difficulty getting the App to install.
Many thanks to Darryl (ClubReef) for sending me the .IPA file (several versions even)!!!
I also finally came across a download link here
http://www.reefsupplies.ca/sb/ from a Reef Central thread that should also work.
Here are the basic instructions to hopefully help others who will attempt this in future...
1. Ensure you iOS device is jailbroken. I am using an older iPod Touch 4G running iOS 6.1.6 which required first doing a tethered jailbreak using Redsn0w and then using Cydia to complete the un-tethered jailbreak using P0sixspwn.
(Detailed instructions on how to Jailbreak your iOS device are available everywhere on Google & YouTube, and will differ depending on which iOS device and iOS version you are currently running)
2. Once you have successfully jailbroken your iOS device, you need to open Cydia and install Appsync in order to install third party .IPA files (basically unauthorized App Store files) Ensure your Cydia is updated, then add the following new Source - repo.hackyouriphone.org (Open Cydia, tap Sources, then Edit, then Add) Once that is completed, do a search for Appsync (I installed the 5.x to 8.x version, which should work for just about any iOS device from the past 5 years)
3. Reboot your device, now you should be able to open the .IPA file in iTunes and install it to your device. Just double-click on the .IPA file you downloaded, it should open up in iTunes automatically. Click on your device icon at the top of the iTunes window and select Apps from the settings menu on the left. You should see the Sunbrite App listed, now just click Install and then Apply on the bottom right and voila you should now have the Sunbrite App on your iOS device.
Hopefully this helps others from the struggles I had getting this up and running... And I own a computer consulting company!
