4-Pack TP-Link Kasa WiFi Smart Plugs (HS103P4) $22.99, Apple HomeKit Supported (EP25P4) $34.99 + Free Shipping w/ Prime or on $35+

Amazon [amazon.com] has 4-Pack TP-Link Kasa WiFi Smart Plugs (HS103P4) for $22.99 ($5.75 each). Shipping is free w/ Prime or on $25+ or $35+ orders (minimum requirement varies by location).

Amazon [amazon.com] also has 4-Pack TP-Link Kasa WiFi Smart Plugs that work w/ Apple HomeKit (EP25P4) for $34.99 ($8.75 each).