Injection Aids. Anyone use them? Do they work?

Our son was diagnosed 9 months ago and has adjusted fairly easily to testing and shots.  We are on 2 injections a day, and of course a whole lot more tests.

We began rotating shots between the arms and the legs.  We encountered a lot of leakage in the legs; so we tried the stomach (ONCE!), and settled on the butt.  Cruising right along with the butt in the mornings and the arms at night; he has decided the butt thing isn't for him either.  Obviously, we can't to them all in the arms.  So, . . .

has anyone tried any of the injection aids.  The ones I have heard of are the "inject ease" and the "i-port".  Any feedback would be great.  Successful or not.