All my projects usually include Blynk in the prototyping phase. It is so easy and fast to get everything up and running. For like 7 projects I just had to buy 1 energy pack and at the end I ended moving everything to a custom blynk server running on a digitalocean $5 USD ubuntu droplet:
That tank works with Blynk for remote controlling 2 electric drills with pwm that drive the belts.
And this wave pool is completely controlled by a nice Blynk dash 