Nowadays calling a mobile phone is also not very expensive so there's no need to worry about racking up a huge bill.

而且现在手机的资费不太贵，所以不用担心会花费太多电话费。

youdao

Even as Baron beefed up his radar business, his weather geeks were racking up patents on software that could interact with gps systems to deliver real-time forecasts to mobile customers.

FORBES: Weatherman