I just came across this Bob Doyle video on YouTube about WaveSpeedAI, a free desktop app which seems to have access to any model you want. No subscriptions - you just pay for what you use, via API usage. It also includes a lot of very useful free to use tools: video and image enhancers, background remover, audio and image converters etc. It looks like a good alternative to ComfyUI. I haven't had time to try it yet, but it definitely looks worth investigating.