83 votesSS commented
I gave up on the official Outlook app by Microsoft, it is so limited in its usefulness and yes, no Tasks, which makes no sense.
I use Nine. It is the ONLY Android app, to my knowledge that syncs Outlook Tasks and Notes. Blue mail does not, ditto AquaMail, TypeApp... The Microsoft To-Do app is completely unrelated to Outlook.
The great thing is the evolution of corporate security policy management on the phone. With the Outlook app, you have to add your 365 work account as a Exchange server phone account, meaning data is stored on the phone, necessitating our work IT to be device admin. I never wanted that on my personal phone and that was an issue for several years. But now, 365 can be properly set up as its own 'type' of account, everything stays in cloud, no need for work IT to be device admin, Nine allows you to choose between device or application security. I recommend device. Nine has to be a device admin on the phone. For whatever reason, I'm OK with that over work IT. If you choose application, it's annoying: you'll have to enter a PIN VERY often to access the app.
There is no equivalent to Nine. It's quite nice. Only glitch (and it seems VERY hard to get this right): a conversation thread should include my latest SENT.