Agree with all the comments here - old iPads make a great dashboard for Home Assistant (and most other home automation systems). If you want to wall mount it there are several vendors that offer surface or flush mount. Get yourself a poe to usb convertor and you're done.

Hot take, but If it's old and/or no longer useful to you, then I would consider selling or trading it in. Apple products hold value better than a lot of other electronics in the same category and you might as well just take the cash and put it towards other homelab upgrades

how old? if its ios 13+ you can install reynard browser which is a full gecko firefox port including addons support.

My old iPhone sits in my kitchen cupboard, connected to a little amp, and I use it for playing music - Streaming, YT, online radio etc. I’ve also got a (flac file compatible) mp3 player for when I know what I want to listen to…

HomeAssistant dash

• Convert it to a kitchen recipe display device and retrieve recipes off of your server.
• Home monitoring panel
• Video/Photo frame
• e-reader

I use mine as a home assistant dashboard.

Dunno if you can do this with ipads, but I've been (idly) considering using old phones to create an Alfred camera system

https://alfred.camera/

Probably not...but it's a fun idea.

iPadOS has really a really good music production ecosystem. I bought Loopy Pro and 3D printed a mount for my MIDI keyboard. It's now a dedicated MIDI controller / looping interface.

Why Apple hasn’t mad the iPad mini a CarPlay screen is beyond me. You can do it with an android tablet but not an iPad.

Like others here, I use mine as a sort of "kiosk" for smart home stuff by using Guided Access to lock it to a single app. If you have a Mac you could also put it into real single-app mode via Apple Configurator policies, but it's more time-consuming to set up and if the app stops working there's no way to fix it short of restarting the entire iPad (whereas you can end Guided Access, restart the app, and start Guided Access again).

Use it as an e-reader for Calibre library?

Previously I used it as a home assistant panel, but everything is so automated no one ever touched it (except the kids, annoying the ever loving crap out of mom).

Now its magicmirror as a calendar display

Wait for someone to crack the bootloader and then someone to get a Linux/BSD working on it and/or code up a bare-metal web view/SDL/uxn/PICO-8 that runs on it. That way, when the App Store stops supporting OS versions that run on it, it can still be reused as generic hardware.

My 6th gen iPad is the only Apple product I own. It's also the only device that refuses to connect to my WiFi. I was going to make it a wall panel, but it's shit.

My wife bought the $100 digital wall calendar from KMart and it hooked up to my CalDav server. I was surprised that it showed zero dark patterns. No vendor lock-in. No ads. No spying.

Client screen for Air Manager.

I have one up that shows transit arrival times for the nearest bus stops.

Mine was so slow it could barely run a website anymore

But monitoring websites - maybe on LAN - could be useful

Or home automation

Media controls?

There was a point where I just had the browser opened to a monitoring dashboard.