Red Squirrel
No Lifer
SMS I'm ok with, at least it's mostly device/app agnostic, but it's supposedly super insecure so I don't use it unless the site forces 2FA then I pick that option. Email works ok too.
The issue I have with apps is that you're locked into a black box, there is no way to back it up or do anything with it. Like what happens if your phone dies or you get a new phone? All the sites I've run to want you to download their own proprietary app so not like you can pick which one, they are all different. Some apps may offer a way to back up the data but not all, so it really depends on the site and their app. I run a custom rom now days so won't be able to get any of these apps anyway. If there was a way to emulate Android in a VM on a PC I would maybe go that route, then I can just backup the entire VM. I just hate to rely on anything that I can't make a reliable backup of that I have full control over. Actually upon quick google search it does seem there are ways, just not sure how it would work for accessing things like a camera (ex: to read QR code).
The issue I have with apps is that you're locked into a black box, there is no way to back it up or do anything with it. Like what happens if your phone dies or you get a new phone? All the sites I've run to want you to download their own proprietary app so not like you can pick which one, they are all different. Some apps may offer a way to back up the data but not all, so it really depends on the site and their app. I run a custom rom now days so won't be able to get any of these apps anyway. If there was a way to emulate Android in a VM on a PC I would maybe go that route, then I can just backup the entire VM. I just hate to rely on anything that I can't make a reliable backup of that I have full control over. Actually upon quick google search it does seem there are ways, just not sure how it would work for accessing things like a camera (ex: to read QR code).