It says "Do not install this app unless instructed to by Customer Support." So, I wouldn't. It may have been written for the EVO, look at the URL. The only permanent fix for Low On Space that I know of is to root your phone, then install the Low On Space fix, that's what I did. It increases the storage space from 150 mb to whatever space is left on your phone's internal memory. It was a little tricky, because when I upgraded to Gingerbread there wasn't room to install. I kept deleting and moving apps, clearing caches etc. until it worked. But now it's fine, no more Low On Space issues. The only thing I've noticed is in one game, it lags a little, presumably because it takes an extra second to store things in the new location.