Turn this phone into a scrolling text sign. Tap the display to come back here.
Preview
Defaults to your phone's current orientation when you tap "Start display" (landscape → Horizontal, portrait → Vertical) unless you pick one yourself here.
Line up several phones side by side (any mix of Android/iPhone — this uses each phone's own clock, not an app-specific protocol). Each phone shows the SAME message, but starts its scroll at a synced clock time with a per-device offset — when phones are the same width and placed in order, the moving line looks continuous across screens. Best-effort sync only (no server): works well on the same wifi/time zone, can drift a little over long sessions — tap "Start display" again on all phones to realign anytime.
If this phone still looks slightly ahead/behind the others after starting, nudge it here (negative = start a bit earlier, positive = start a bit later) and tap "Start display" again — this is a manual correction on top of the clock-based sync above, for closing small leftover drift.