AS already said, check permissions before installing, and if you're not happy with what's wanted, don't install it. For example, if a (say) music player wants to access your contacts list, make calls and send texts I'd be VERY wary as phone functions are not necessary to the app's stated purpose.
(There's supposed to be a Russian video player that wants to make calls and sent texts. It sends texts to premium rate numbers at $5 a time).
Email the developer to ask for an explanation. I've done this a few times, and got a polite response with an explanation. Doesn't mean I trust it though.