With the release of Tapo version 3.0, TP-Link integrates their two lines of smart home devices into a single application, reducing the number of apps needed to control their devices.
Additionally, the update claims improvements to the user interface, optimized camera features, a sleeker status page, and faster responses and startups.
The blow post also suggest that improvements to lighting effects, smart actions, geofencing, and a dark mode will be coming in the future.
I think the best takeaway is that I can have one less app on my phone!
In the 1st step, maybe a year ago or so, they updated the Kasa app (v 3?) to only function with account and while being logged in at TP-Link servers to use your devices. And in now the 2nd step, they integrate Kasa into Tapo, which was always account-bound. The 3rd step is then probably the discontinuation of the Kasa app.
Kasa was their more premium product line, that was usable without internet connection and without manufacturer account - which is why I paid more to get those instead of the cheap Tapo products. But now my 'smart' power outlets are in a box in the basement collecting dust and I cannot recommend anyone to spend money on TP-Link smart products, as they remove features after sale.