As more and more people these days do away with landlines, minutes can add up fast and lead to big, unwelcome bills. A growing number of apps can help keep voice and text data usage – and bills – in check. Here’s three of them: One of the hottest is Pinger Textfree, a free app that gives users a real U.S. phone number that allows for texting or calling anyone. Pinger uses a WiFi connection so texts and calls don’t count against your cell phone minutes or plan. One of the coolest things about Pinger is the fact users can keep in touch with friends, family, and businesses around the…