Here is another robot arm that combines with the Raspberry Pi to teach you a thing or two about coding. The Adeept RaspArm-S is a robotic arm kit for Pi 4, 3B, and 3B+. It can be controlled manually or via an app. RaspArm-S also has a gripper that opens 1.25 inches.
This kit ships with 4 suction cups, 4 x AD002 servos, 1 x OLED screen, an acrylic gripper, and other components you need to put it together.