You asked this over a month ago and since you still haven't figured out a use for it, that probably means you don't have one.
At some point in the not-too-distant future, your old device's battery will be kaput, meaning it will have to be plugged in at all times because it won't hold a charge. That will greatly limit the number of opportunities for you to use it.
It's no longer receiving iOS updates, so it can't run the latest apps. That means that most of its usage would be media playback or web browsing. Someone else earlier suggested using it as an iPod, but apparently that idea did not appeal to you.
I suggest you donate to charity while it may be worth something to someone else. Right now, it doesn't appear that it has any worth to you at all.