Probably it is a problem on your browser (the program you use to surf the internet).
Mitify stands as an innovative project that takes advantage of the latest technologies so we have preferred to spend the time required to support obsolete browser, in product improving.
All modern browsers are fully supported: people using chrome and firefox usually also cares to keep them up to date, but if you use Internet Explorer, make sure you have a version> = 10.
If you have an older version it is certainly more convenient to install chrome rather that put effort in updating internet explorer!
The best results in terms of speed and fluidity are achieved with chrome and this probably is not only valid for mitify.
Check and download the latest browsers version