The Mooer S1 is a great product which consists of software and hardware. The hardware is well described on the Thomann website and also by various publicly available reviews. The software you have to figure out yourself by trial and error once you have the product because, the software will not start up unless it can see the hardware via Bluetooth.
The software enables you to setup how you want the hardware to work including what you want the four physical stomp switches to do. By default, the stomp switches lets you select one out of forty patches. Also with the stomp switches you can record loops, tune and control the drumming machine. According to the description of the product on the Thoman website, the Mooer S1 has "126 Built-in effects". That is not untrue, but it doesn't explain what the product can really do.
The software lets you design new patches where you mix amplifier, cabinet, overdrive, reverb, delay, compressor, harmonizer, noise gate, phazer, tremolo, auto wah, touch wah and many more with individual tone and volume sliders for each. Also there is a three channel mixer to mix the instrument output AFTER effects with the input from USB of Bluetooth, and theres is a master equalizer, gain and volume.
The output of the S1 can be set to "Interface mixer" or "Power amp". I thought this was so I can use a stereo set if no guitar amp is available, which would make sense for a portability solution, and which is probably also what the software designers had in mind. It doesn't work. As best I can tell, the S1 does exactly the same whether you set it to "power amp" or "Interface mixer". I solved this with an external preamp.
Also, it would have been nice with stereo inputs, so both guitar and voice can go through it. It has stereo outputs but not stereo inputs, which seems kind of illogical, and there is no balance slider either, like you would normally have on a stereo output.