I've been using FreedomPop for almost a year. Currently I'm using the 4G LTE sim in AT&T network with free 200 minutes/500 texts/200 MB (increased to 700 MB after connected with 10 FreedomPop friends). AT&T's coverage is excellent, and I do have problem with making/receiving phone calls using the FreedomPop app. Some months I pay $1.99 for MMS service. So far I'm very satisfied with FreedomPop.