The issues you mention do not necessarily go away with a new App because they are caused by firmware inside Tello.
No control after takeoff / shortly before touching ground: Tello is sluggis in low altitudes. Extremely sluggish when very low. Landing with some wind is asking for trouble (be blown away).
Delay response: Again, Tello has a delay when following commands in the slow / video mode. Nothing an app can do about this. This is firmware. If the app is OK in fast / sportmode then its not a fault of the App but Tello making efforts to keep the drone (and the image) stable.
IMO these two point shave gotten worse with every new firmware.
Video lag: Normally the Ryze app isn't too bad. 230ms is what I measured. I managed to get around 170ms for telloFpv which isn't bad for a wifi transmission. That is in slow / video mode meaning that image stabilization is on. Sport mode without image stabilization may be a bit faster, but i haven't tested