I wonder what the OP did. @Hari_Seldon, any update?
After reading over all the helpful replies, I decided that something enough to fit under the covering case (which also acts as the on/off switch) would be best and so I have ordered
It is supposed to come by early next week and I will let you all know how it works.
That page doesn’t work; I think it’s linked to your account and only works when you’re signed in as you. I think this is the item you meant to link to:
I have a related question and I hope you won’t mind me piggy-backing it on here.
Do the newer devices that can work on iOS or Android allow me to set them to the iOS network, (which has many more users) and then track it on my Android device in any way?
Thanks. I look forward to hearing how it works for you. I assume you will test how well it works to find the e-reader?
Heh heh. It says find your bag etc. from your phone. The thing I lose the most often is my stinkin’ phone. I’ve left it at Dollar General so many times they know it’s mine and call my daughter. 
First I have to find that e-reader. It is currently in her purse and I hope it stays there till they arrive. She has two other e-readers but they are old and their on/off buttons do not work well. One I can turn on only by rebooting. If this works, I plan to toss them.
I’m pretty sure it doesn’t work that way. I think you would need an Apple device to register the tracker with Find My, just as you would need an Android device to register the tracker with Google Find Hub.
There are some super clunky workarounds, but you would still need a friend or a person you trust with an Apple device to help you track it on and Android device.
Thank you. That’s the kind of thing I was unable to figure out from the app description or the ads that I saw. It seemed to me that it should be possible for me to turn it on, tell it what network to go onto and then use the app to find it on that network. But that obviously isn’t the case.
I usually misplace my iPhone locally, FindMy tells me what I know, that its at my house.
I use a Chromebook, so perhaps putting an Android tracker, that can read close distances (on a ledge in the garden etc) would be best for me? Suggestions?
Been reading up on the trackers, they seem to work great from the phone, finding other devices.
Some of the trackers (i.e. Chipolo) do have the ability to send a signal back to the phone and make it ring. I can’t tell you about the iPhone because i’m only investigating Androids at the moment.
Call yourself (from another phone 
)
Also you can make the phone beep, just run Find My on the same Apple account on a laptop or other device.
Concurring with what @zbuzz said, the dual device trackers can be set to iOS or Android, but not both at the same time. There are some subtleties though.
Once put in AirTag mode, and paired to an Apple device, they can only be tracked by an Apple device. The web based Apple FindMy does not show AirTags and similar trackers. However, when put in Google mode and paired to an Android device, the tracker can be viewed from Google’s web based Find Hub.
So, an Apple device can log into the appropriate Google account, go to Find Hub, and see the Android-mode tracker, but an Android device cannot see an Apple AirTag. If you want to view things from both Apple and Android, then the best option is to make it an Android based tracker.
This does not solve the problem of using the larger iPhone network. I’m not sure that is an issue, though. There are lots of Android phones, and they do not require a special app to support the Android based trackers. At one time some trackers did require a special app to work on Android; don’t buy those.
Another advantage of going the Android route, if it is an option, is that Android only trackers may be much cheaper. I recently bought a 4-pack of the MiLi MiTag Android only ones for $25. That’s about the price of a single AirTag, though non-Apple trackers are cheaper. At about $6 each, it’s worth it to put a tracker on just about anything of value that is easy to lose.
I used to have another one, worked great calling the first
!! Even found it buried in the compost pile. Lost it at the beach once and called it, some person had it and answered!! Now I just have the one. Primarily thinking if volume is off or its uncharged. Maybe a tracker on it?
You can track it via Find Me, you just need to access your Apple ID from another device that you can find and use.
Just an update on my order. I made the order on Wednesday and they predicted delivery in 3-5 days. They also sent me a tracker for the order. Today is five days from my order and my package is still in an airport in China. Not a good sign.
It may only register with IOS but I’ve got an app on my Android phone that will talk to it if they’re nearby. e.g. if I’ve misplaced it in the house.
If I leave it somewhere else, it’ll only register if someone with an iPhone has been nearby.
A tracker for your tracker?
Finally, the Mi-card arrived. Not without some difficulty, I installed the app, then attached the card, jumped through some hoops and then tried to operate it. I opened the app successfully, but there was no way to search for the card and I am totally stuck. When I tried to go to their web site, Firefox strongly recommended against that so I didn’t. All in all, it is not ready for prime time.
Maybe if you are more comfortable using phones than I am you might make a go of it, but I couldn’t. I could not work out how scan the QR code and had to find out what the NFC area on the phone is, in order to pair the card.
Are you using an Apple device? Those should already have the “Find My” app installed on them. Android should have “Find My Device”, “Find Hub”, or a similar name. Not some weird app.