A very nice extension if one does not want to frequently use his/her phone. However syncing has become a big issue. At least I cannot sync via the syncing function of firefox browser. This can cause problem if one is migrating to a new device.

此扩展强迫用户额外设置一个主密码才能使用

Since I don't have a smartphone, it's very convenient to have this add-on installed. However, when copy/pasting the code three unnecessary spaces are added to the it. With ProtonMail I have to manually delete them. Other than that, brilliant!