Please take discussion of future developments, complaints, design ideas, what support said, etc. to the discussion thread:
"SmartThings Classic" vs "SmartThings (Samsung Connect)"
This thread should only be used to list specific differences between the two apps. If we get off into all of the other discussions, this thread will cease to be useful.
Thanks! 
A date for deprecation of SmartThings (Classic) App has not been officially announced anywhere.
As usual, random information like this from SmartThings Support is not trustworthy.
New app can now set hub connected device settings. This is @krlaframboise dome siren DTH. I have t tried changing anything yet, though.
I just checked some of my other handlers like the Zooz Smart Switch and those settings are shown too.
I wonder when they made that change?
Today I think.
Is it safe to run both the classic app and the new app on my phone? Even if I’m using my phone as a presence sensor?
Yes.
The presence sensing for the two apps is completely separate. You’ll only want to use one of them as presence sensor.
I ran both apps for close to a year with the classic app has presence sensor. Started having long delays with that app triggering presence changes so I removed the sensing in the classic app, set it up in the new app. All working well, both apps still installed.
iOS has trouble with mobile presence when both apps were installed. I got sick of fiddling with it and deleted the Classic app from my phone. Only have it on an iPad now.
So, I haven’t used the STSC app in a long time. It looks like a lot of the missing items from the v2 app are now there. Am I right? I feel like I could switch over to this now. I see custom SmartApps. It looks like webcore is working. I understand the change from routines to automations/scenes. I have several custom device handlers that also seem to be working.
Is it time to come back to the fold? 
Is not perfect yet, but improving. I keep finding the need to go back to Classic. Some Settings for various devices (custom or native) are not working. I stumbled on two yesterday, changing Settings for HEM custom device and changing setting for builtin Ecobee. Also, converting Classic routines into scenes didn’t go well. I reached a point where new scenes were not saving, I guess I reached my behaviors limit.
WebCoRE doesn’t arm/disarm STHM in the new app yet but you can use automations to do that
im trying to update some of my thermostat DH’s to work better in the new app. ive got them showing but have 3 diferent DH’s, Tkb unerfloor thermostat, sleapy thermeostats and awake stat.
They all look diffent in the new app, the sequenc of the controls are diffent, one has duplicate heating/cooling controls, one dosnt show battery. is the a guid on how to lay out the capabilites etc?
I have the same problem on iOS. If the Classic app is installed, the new app lets me enable presence, but turns it off, I think the first time I enter or leave the home zone.
I have my whole house setup as a security system using ST and a V3 hub.
The one area that is flakey is arming and disarming the system when my wife and I come and go.
We are using our cell phones as presence detection.
Should I be using the classic app, or the V3 app for this ? Is one better at presences than the other ?
And does it cause issues if I have them BOTH installed on my phone ?
I am using two @RBoy apps , but other than that all standard devices and automation.
The same in my experience. Both apps with locations services enabled causes issues on iOS.
Except as noted by @Automated_House it’s fine to have both apps installed.
I used presence in the classic app until about three months ago, then it started getting flakey. Long delays to show present or absent. So I disabled presence in the classic app and enabled it in the new app. That’s been working better…
How do you disable presence in classic, it’s been a while and I can’t find it
Hmmm. It’s been long enough that I don’t remember, either. And Google isn’t helping.
You can go to your list of devices and remove your phone. That might give you a warning about where it’s used.
Presence in the new app does not use a device representing your phone.
The 2.18.1 update of the classic app started causing an undismissable notification about “updating your mobile presence”. This was happening to me even though I’d stopped using it in that app. Deleting the phone/presence device got rid of the notification.
If memory serves me all I did when I switched to Life 360 a few years back was just delete the smartthings phone presence devices from my list of devices. In the classic app, not the new app.
Did that, still getting the notifications when leaving, must be new app?
