The only reason for existence of such app is imo stealing more of personal data. Ah, and to push more adds. In browser you can add an adblock, but if it's packed in an "app"...
Would I run it? Only from an isolated container.
Android apps already run in isolated containers, and it asks you for any permissions it wants which you can refuse.
Mobile permissions systems are a patchjob. They prevent some stuff, not all, it's still possible to collect info on people's habits. Networking behaviours, testing and gauging whether or not users react to notifications at certain times of day or not, asking other apps and services for tracking IDs to correlate with. Not to mention many apps also refuse to work until you grant permissions, forcing the user to concede anyway (for the 99% of users who don't have a way of faking data/permissions for an app).
Exe is almost completely right, the main motivation for an app over a website is to collect more personal data on users. The other motivations are being able to send notifications to user (ie spam them more effectively than emails) and to satisfy cultural requirement in a business (CEO:"what do you mean we don't have an app? How do our customers even function?!?!" or "look at our app user growth statistics! Growth!").