Second screens from spare devices
That old iPad or Android tablet in a drawer can be a genuine second monitor. Display-extension apps stream your desktop to it over WiFi or USB — often for free.
Why a second screen changes everything
Research beside your writing, a call beside your notes, code beside the preview. A second display consistently ranks as the highest-impact productivity upgrade — and software can conjure one from hardware you already own.
- Reference material stays visible while you work.
- No more alt-tab roulette on video calls.
- A tablet on a stand is a perfectly good travel monitor.
How it works (and what limits it)
A driver on your computer pretends a monitor is attached, then streams that monitor's picture to the app on your spare device. The bottleneck is the connection: great WiFi feels near-native; busy WiFi adds lag.
- USB connections are the smoothest — use them for daily setups.
- 5GHz WiFi at close range is fine for documents and browsing.
- Fast-motion video and gaming are where lag shows most.
Picking your tool
Free-first: Spacedesk covers Windows hosts brilliantly at £0 for personal use. Smoothness-first: Duet Display's subscription buys noticeably lower latency. Apple-only households already own Sidecar.
- Windows PC + any spare device → Spacedesk (free).
- Daily professional use → Duet Display over USB.
- Mac + iPad → built-in Sidecar first; Luna Display for wireless polish.
- Android tablet as a drawing tablet too → SuperDisplay.