by Edited by Lisa A. Grimaldi | May 14, 2012

Onavo appOnavo Extend, a free app compatible with iPhone, iPad, and Android, extends data plans by up to five times. The app is particularly helpful when traveling abroad, where data overage fees can be exorbitant if no Wi-Fi access is available. For example, when combined with AT&T's global roaming data add-on of 125 MB ($49), Onavo lets iPhone users download up to 1,000 e-mails every day for a month without overage charges.