always look at the comments.most of those apps dont do a good job because its still wanting to attach things to the internal even if you swap it.
i recommend xperion rom and link2sd and learn how to use it,or if you dont want to use xperion rom then try the sdhack method but choose one or the other.if your wanting to use 12b firmware you want xperion and link2sd though.
the phone will never say insufficient space if you have a big enough card,but a low disk space warning might show up every now and then,but everything will still work because of your external card space.
look up symlinking because thats basically what link2sd does,i paid a lil more for plus features to also link internal data over and have it clear cache every hour.no insufficient space,no problems XD