Hi all,
I drive a lot and wanted to toggle my Sonoff relays from the car screen without reaching for my phone — so I built a small app for it. Sharing it here in case others find it useful.
What it does
Adds a dashboard of tappable buttons on CarPlay / Android Auto.
Logs in with your normal eWeLink account — no developer keys needed.
Lists the devices in your account and supports multi-channel relays (deviceid#0, #1, …) the same way the eWeLink app exposes them.
Geofence automations: trigger actions (or Home Assistant scenes) automatically when you enter or leave a zone — e.g. open the gate relay as you pull into the driveway. Notifications show up on CarPlay too.
A bit under the hood
Region hosts: *-apia.coolkit.cc
App auth via the X-CK-Appid header + HMAC-SHA256 signature over the exact request bytes
Handles the automatic region redirect on error 10004
So it’s not a wrapper around another service — it talks to the eWeLink cloud directly, same as the official app.
Honest note: it’s a paid app — $9.99 one-time, no subscription. I’d rather be upfront about that than bury it. It also supports Home Assistant, MQTT, Tuya and Shelly in the same app, but eWeLink is the part that’s been tested most.
Would love feedback and feature requests from people who actually use Sonoff gear daily. Two questions to the community:
Which relay/device types do you use most? (Multi-channel? Sensors?)
Would a geofence trigger (drive-up automation) be useful in your setup, or do you prefer manual buttons?
Happy to answer any technical questions.
Lucian