It's adequate for a basic signal generator for sine, triangle and square waves. You have to change jumper settings to get the full range of frequencies and you will find if you change from one signal type to another - say from sine to triangular waveform you will have to adjust the waveform to take out distortion, which is pretty annoying.

Be aware that although it comes with a USB cable it will not run off 5 volts. The integrated circuit this device is based around needs at least 10 Volts. Anything less and it wont work properly, or at all. It may mention this in the Chinese text on the back of the circuit diagram. I can't read Chinese- but there is reference to 9 - 12 v DC amongst the Chinese writing. I got the data sheet for the integrated circuit and it suggests 10 to 36 V DC

The Circuit diagram was a bit difficult to read and you will need it because although the component identifiers are on the PCB the component values are not.