Hi
I had a same problem some time ago, I've installed Font Zoomer and it completely messed up my phone, I had to shut it down. And what did I found out afterwards?
Possible solution 1:
You have to install most recent version!!! Older versions no longer works and will not open on your phone. Links below leads to nokia store and creator's homepage, where you can
check for updates
http://store.ovi.com/content/47422?clickSource=search&pos=1http://www.somyac.com/Possible solution 2: You (accidentaly) deleted some important files that made app freezy. Reinstall and try to boot it again. If you had full version and uninstalled it, just go to store and download it again, once you pay for it you can re-download it anytime.
I hope I helped you buddy