Taking back what's ours

• If you live in the United States and you have a remote-controlled garage door, chances are it uses MyQ. MyQ would let you open or close from your smartphone. The way to set this up would vary but it can involve a service running locally (at home) that makes requests to the MyQ API servers. MyQ started monetizing this, so they're killing these previously-working revenue-lacking integrations. If you want to control your garage door remotely from a computer or a smartphone, you now need to pay a subscription. Or do you? Paul Wieland probably thought to himself "I own this garage door, I bought it, I'll have it open and close remotely if I say so" and he built a little board that he now sells: the ratgdo. You plug this thing on power (USB) and you wire it to your garage door box (easier than it sounds), set it up via its web interface and boom, it all works again. Except now it's self-hosted. By the way, ratgdo stands for Rage Against the Garage Door Opener :)
• Whenever you add a "smart" device to your home network, this piece of equipment will go and talk to a bunch of servers. This will happen without you knowing. Maybe your tv is looking for a software update. Or your smart plug is confirming its on/off status. These calls range from essential to nefarious (ads, telemetry, spying). By installing Pi-hole on your network, all your home devices will ask Pi-hole for DNS resolution. Pi-hole can allow some calls and ignore others when an appliance or software tries to find out which machine-usable IP address (e.g. 142.250.81.238) lies behind a human-usable name (google.com). In effect, Pi-hole cleans your network of noise requests and eliminates a lot of ads from your digital experience.
• Coolbot is a piece of hardware that lets you hack an AC unit so that it keeps on pushing cold air beyond its factory-set limits. So, instead of a super expensive tiny cold room, you can jury-rig a colder container for the fraction of the price. Or you DIY your own.
• Umbrel is a self-hosted Bitcoin node for the Raspberry Pi. It's not a miner, it does not try to solve puzzles and mine bitcoin. It just assembles the blockchain as the rest of the network knows it and it lets you do cool things like host your own mempool.space or create lightning channels. Having your own blockchain locally means you can query it. You can point your clients to your own copy of the blockchain. This way your clients don't have to use third party servers. Not only does this make you a legit participant of decentralization, it also provides privacy. Because whenever one of these third party services receives a request from your client, it is able to tie a very random public address to your IP address. Bitcoin is pseudonymous but if a public key is only ever enquired about from a single IP, it's not a stretch to think there is a strong chance that IP owns the coins residing at that address. Why feed the surveillance machine when you can avoid it?

I love these hacker projects. Which killer app in the same vein did I fail to mention?