Phone camera works pretty good, get a decent tripod and/or mount. GoPro or other action cams are good cheaper alternatives, but the fisheye lens is not the greatest for the application. Small rig and Joby brands make pretty decent inexpensive mounts, fluid heads and tripods. For phone filming, a power bank for charging, handheld remote, and a good fluid head are great to have. I only film for my own enjoyment, leaving my good mirrorless camera at home saves weight and one less expensive thing to worry about.
