The Version of This Question That Matters
Not browser versus app, but official versus repackaged. A genuine operator app is a reasonable piece of software with a short permission list; a repackaged build with the same icon is a different program wearing the same clothes. Nothing about the choice between a tab and an install protects you from that — reading the developer name and the permission list does.
Which is why we keep pointing people at the browser for casual play. It is not that web builds are inherently safer software; it is that the browser removes the entire category of question, and does so without asking you to be careful at the exact moment when carefulness is least likely.
If You Are Going to Install Something
Read the permission list in full before tapping accept, check the developer name against the operator's own site, and never install while you are logged into banking on the same session. Those three habits catch most of what goes wrong here.
The full install checklist is on the apk guide, and every guide on this site is listed on the home page.