I've looked all over google but have yet to find what i'm looking for. I just want a simple Indicator that shows the remaining HDD space for my drives. Doesn't need to be fancy because it's being used on my laptop and i only have 1 HDD.
Install indicator-sysmonitor from Is an Internet connectivity indicator applet available for the Unity panel?.
You'll need to create a script that will contain a call to
df or something similar and then parse out the required information. Get the script going in the terminal first to ensure you have the correct value before adding it to the indicator.