Software that burns down the server of any website that asks for data they don’t actually need.
A browser addon that utterly floods advertisers and trackers with dummy data. A single person using it is easy to single out. A thousand start to eat into the profits. 100k should make them go offline (DDoS’ed) with an interesting frequency.
health smartwatch app, with sleep n all features in some opensource format that could use any other app data… utopia, i know
GadgetBridge (Android). You need one of the (many) supported smartwatches. Data is easily exported and processable with, eg, R.
Well working, good looking airgaped password manager
There are some, but they are mostly like proof of concept
Keepass?
Love keepass, but I mean something different
A password manager that can keep passwords on one device, and use the passwords on the other, without the storing one being connected to any network, etc
KeePass with inputstick. It’s a device that plugs into a USB A port, and your phone talks to it via Bluetooth. It emulates a keyboard (and mouse if you want), and there’s a KeePass plugin for KeePass2Android.
You open one of your password entries, click the username, and it types the username on your computer via inputstick. Ditto for passwords and totp or other fields.
You can also use inputstick to just remotely control your computer, albeit locally only and without a monitor connection. I’ve used it to control my raspberry pi or android TV, aside from password entry.
With this, you can have your password database be completely offline and your computer have no lasting knowledge of your passwords. Of course, a keylogger would still get the passwords that are “typed”.
I’ve had one of these $40 devices for a few years. I don’t use it too often, as I tend to synchronize my KeePass database on all of them, but it does come in handy. I wish the developer of the hardware made a usb-c one, but it works with usb-c to usb-a dongles.