The full review
Series 4 was the Apple Watch's big redesign — a 30% larger display in a slimmer case, plus the first ECG sensor on a mainstream smartwatch. On the renewed market today, it's the most affordable way to get real Apple Watch features rather than a glorified notification band.
For Kenyan iPhone owners it covers the essentials: calls and WhatsApp on your wrist, workout tracking that actually motivates, fall detection, and heart-rate alerts. The 44mm case fits most wrists, and straps are cheap and plentiful.
Honest caveats: it no longer gets watchOS updates (it stopped at watchOS 10), and battery health on renewed units is the key thing to check. For a daily-driver watch, a Series 6 or later is a better long-term bet — but for the price, the S4 still earns its place.
Key features
- Larger edge-to-edge display (40/44mm)
- ECG and heart-rate monitoring
- Fall detection and SOS
- GPS + cellular variants
- Swim-proof 50m water resistance
