I've been playing with a Flic Hub LR and some Flic 2 buttons. They're "smart home" buttons, but for me they've got a killer selling point: rather than locking you in to any particular cloud provider (although you can do this if you want), you can directly program the hub. This means you can
flic,
nas,
letters,
parcels,
hacking,
houses,
delivery,
iot,
technology,
slack,
huginn