They communicate via Bluetooth to an app on your phone so the screen size doesn’t matter too much but there are other device options with a bigger screen such as this Lilygo T-Deck which I am about to try. nostr:note1xf66ykdxl7d7ey5yh8437z0q6shgy749c6n6g6ng0mkvmu5x0vgsed0jr0

You use an app on your phone via bluetooth. Meshtastic has Android & iOS apps that you control the device. You also use the app to type messages and then send them via the device so it's all dependent on Bluetooth & radio not cellular

if only, :) https://www.youtube.com/watch?v=d2OXlVcRYrU , https://www.youtube.com/watch?v=AXSOZC590mc , https://www.youtube.com/watch?v=RHdbWJzSpDk