Time-consuming, but avoids "Plugin Missing" errors when sharing project files.
Drag your background footage (the person holding the phone) onto the timeline. Drag your foreground footage (the viral video on the phone) onto the track above. Mask To Transform Plugin For Adobe Premiere Pro Free
Select the top clip (the viral video). Go to the Effects Controls panel. Find your Mask to Transform plugin. Click the "Pen Tool" (or "Draw Mask") inside the plugin window. Trace the screen of the phone. follow these steps:
While "free" is attractive, you must be aware of the trade-offs. Mask To Transform Plugin For Adobe Premiere Pro Free
Once you have downloaded a free .exe or .bundle file, follow these steps: