Focus on task
As a general rule, try to stay away from anything that requires users to remember to go back to your Tini App to complete tasks, they most likely won’t. Once the user has entered a "complete-the-task" flow, help them finish the task within the shortest amount of time possible by removing other potential distractions on-screen.
Stay on the screen
Solve most of the problems on the same screen and avoid leading users to a new one if not necessary, because the page refresh and forwarding can make users feel uncertain about the next step, in addition to disrupting the user's mental flow.