The ability to create my own integrations with other systems using API's made this tool very easy for me as an end user of their service! I had no issues while building out our custom app or integrating into it from Salesforce (we use SFDC). Their support team was also great at helping us get up speed quickly. Nothing really - they have been responsive in answering questions we've asked about what APIs are available through them so far which has helped greatly!! We're looking forward to working more closely together going foward once our apps go live next month. They offer several different types/formats of SDKs such as PHP & Python depending upon how you want integrate external services like Zapier etc. It helps give flexibility if not too many options can be overwhelming!