I like that you can create your own APIs with this service in just minutes without any code or programming knowledge! The only downside is not having more options to customize things such as custom domains etc but it's easy enough for anyone who knows what they're doing to get up-and running quickly using their existing domain names/hosting services.
We use Instawebapi to power our web applications (we have two - one internal & one public). It has been very helpful because we don't need to worry about building out servers ourselves since everything runs off of AWS instead. Also, by utilizing Cloudflare CDN caching, these apps load super fast even when there are lots of users online at once.