Sorry if this had been asked and answered before, but is there a squad builder iPhone app? I've been looking this morning but haven't found one. Maybe I'm just dumb and not searching the right words or something...

Battlescribe mobile works pretty well for me. Just make sure you connect it to a source that continually updates its files like:

http://battlescribedata.appspot.com/#/repos

Works really well for me, and they update it pretty regularly. Good luck.