免费语言学习软件Duolingo 近日宣布将推出 App 内购买服务：Duolingo Plus 。目前 Android 版本已经加入了 Duolingo Plus，iOS 新版本也将在短期内上线。

The product also continued to evolve, with the introduction of Duolingo Plus, a premium subscription allowing users offline access and an ad-free experience when they pay a monthly fee (later to ...

Duolingo Plus is $6.99 per month after a 14-day free trial. This removes advertisements and adds features such as unlimited ...