I’ve used the advantage of using my phone larger screen as an external monitor. Useful for studio and location shots. landscape etc and especially useful for me in re-photographing my negative archive. [Not much cop in a riot though] .
How to Turn Any Android Phone Into a Camera Monitor
Paul Figueiredo
If your camera doesn’t have built-in functionality to use an Android phone as a monitor, try this workaround
https://www.makeuseof.com/how-to-turn-android-phone-into-camera-monitor
What Software Do You Need? – this one works better for me.
The app we recommend for this method is called nExt Camera, available for Android on the Google Play Store.
nExt Camera – USB
https://play.google.com/store/apps/details?id=pl.nextcamera
No Budget? No Problem
DIY filmmaking with inexpensive home-brewed solutions like the one we just described can be a reward in itself.
While this method won’t be competing with the likes of Atomos or BlackMagic Design with their Ninja and Video Assist series of monitors respectively. But thanks to the nExt Camera app and some inexpensive accessories, those of us with lower-end hardware can optimize our filmmaking skills a little bit more than we could before.