I like that it is easy to use, has an intuitive interface with drag-and drop features for layouts, makes building mobile apps very simple even if you are not tech savvy at all! It’s also really affordable compared to other app builders out there (especially when comparing price per month).
There aren't many things about this platform that I dislike - maybe more options would be nice but they have plenty of them already so no complaints here either. We used mobiMatic in order build our own business management software which we then sold as part of their service package.