There is are more easy way to know if a app can be trusted or not inside google playstore
1. Look for bad reviews under the app comments, don't mind the good reviews as scammers can do that themselves
2. Look at the many times the app have been downloaded, if it's a very reliable app it will have over millions downloads
3. If there is no reviews available then something is wrong, that should raise an eyebrow ain't it?
Most very reasonable application have bad review under them. Some people are not calm enough to see if their phone meets the requirements for the app they are installing and when they face issues using the app, they give negative feedbacks... So this cannot totally decide a bad app.
I feel the best way to get an application is from the authorized website of that application. That way one don't fall for cloned application.