One thing to consider is that fingerprints are actually LESS secure in some ways. Nobody can force you to tell them your pin, but they can definitely knock you out and use your fingerprint to unlock your phone, email, bank accounts, etc.

There should definitely be some though put into WHEN a fingerprint is an acceptable authentication. I'd definitely require the PIN after a reboot, at a minimum.

Yup. In 2018, this should be a required feature for any app that needs authentication.

This feature is very important to me as it is very easy to watch a PIN being entered and potential access to my email, in case of a stolen phone, is a huge attack vector to other accounts.

Many consumer tech companies and their products actively deprive their customers of any privacy as a integral part their business plan. They continue to increase profits margins by surreptitiously stealing all of your personal information they can harvest then reselling to government entities, law enforcement, data aggregators/profilers, advertisers etc.

This disturbing trend is now a tidal wave as tech startup companies routinely follow the same business practices pioneered by Google, Apple and others. A customer's personal info is the product, the device or service is only the collection mechanism.

tl;dr
Finally my point is this:

There is no company, device or service that I would willingly allow to obtain my fingerprints or DNA. The recipient *will* sell the data. If not, governments will subpoena or simply steal it to supplement their already vast collections of personal data, simply because they might 'need' it in the future.

Cost <> Benefit IMO

I would not share my fingerprint with Android / Google. If I trusted Google, I would use Gmail, not Protonmail.

I really want this. Was used to it on iOS but switched to Android. Was very disappointed to switch back to a pincode.

I really wish this feature were implemented. iOS got this feature over a year ago and it's been 1.5 years since the fingerprint API was released for Android.

Please don't treat Android users like second rate citizens.

For android or Apple would the use of the fingerscanner be great.

btw still it's not featured in app u can use fingerprint authorization through native browser without a protonmail app at all, kinda more secure way

imho this feature is more secure than a PIN entry, because PINs can easily be watched as you type them. Strangers can use them if they get their hands onto your phone.

Of Course they have to have access to it, but this is only security through obscurity

I think many users would appreciate this, since fingerprint sensors are much more common nowadays. Android users should not be let down against iOS users.