Nothing, best option to build an application without much hassle or cost involved is just awesome! Our team was able to develop very quickly with this platform which made it easier than expected when we started working together in our new startup that I co-founded last year (the same one as my employer). The customer support from kandasoftware development could be better sometimes but they are always there if you have any questions regarding your project's progress at anytime - even late night hours :) If anyone wants fast results then go ahead using them since all what i've said here can easily work out well enoughtly within few days/weeks time span after starting up again a fresh app building process wich will take way more effort otherwise.