I found some app on GP which provides possibility to review other dev’s app, collect credits and be reviewed by them in return.
Is this compliant with Google Play policy? From my point of view this is legal, because we get honest review from real person, not bot.
What do you think about it?
Clearly - not compliant.
Google recently (this year for sure) updated the Policy - exists chapter that says:
“Developers must not attempt to change the placement of any Product in the Store, or manipulate any product ratings or reviews by unauthorized means such as fraudulent installs, paid or fake reviews or ratings, or by offering incentives to rate products.”
The “manipulate … offering incentivies to rate …” part is exactly what cross reviews are.
I agree with you. Illegal applications are not published on GP. If these sorts of application are available on GP it means these are legal applications.
That means nothing. Google does not approve any app. The Google team can remove apps if they receive compliant and after that will check and decide about removing the app.
Also, it is possible that the app itself is legal and do not brake the rules of Google play developer policy, but the usage of the app by developer in order to manipulate the ranking of his own app is not compliant with policy.
For example, publishing a media player on market is legal, but using the player to duplicate copyright material is not.