I'd say the Source Audio C4 is the most versatile pedal on my board at the moment, if you own a personal computer, you can layer effects on top of each other and it's almost like the sky is the limit.
My smartphone wasn't very friendly with my SA pedals and I might have been able to fix that. My laptop is easier to use anyway. Frankly all three of my source audio pedals kind of blow most of the pedals I've used out of the water straight out of the box, though there are plenty of pedals out there I haven't use that are likely pretty awesome, but they all easily fill the role of quite a few pedals imo.