This project provides a compact WLAN-controllable signal source up to 200 MHz.

Using literally 4 wires, a Pico W and a Si5351 breakout board you get a very affordable and compact device. Custom Firmware: The Pico W hosts its own WPA2 access point and serves a web interface to configure frequency and output behavior directly from the browser. Custom case: Tight 3D-printable case. Power supply: From USB.

This provides a nice and easy to use high frequency signal source for your workshop, controllable with your cell phone. As you can see from the images, depending on what kind of signal you need, heavy filtering might be needed ;)

Sources are on github, more info at casparlab.eu