How to contact app reviewers of a different app for feedback?

I am developing an Android app which would be competing with a few different apps in the same space and I see a few bad comments on the competitors' apps.

I am seeking advice and insight on what the end user really wants. I thought that through the reviews, I can go to the reviewers' Google+ page and ask them what they would like different or just some of their thoughts. Is this a good idea? Would this creep the person out? Or is there a better way to do this?

I know I would help an entrepreneur contacting me randomly but that is probably because I am one of them.

I am an entrepreneur and I get what you are saying. But if someone followed me onto Google+ via a review that I wrote on the Android App Store - it would creep me out a bit.

I realise that Google does allow you to link-dive on the reviewers Google+ page - so you'll be able to contact them - but if I were you, I'd contact only the extremely frustrated users as they would welcome a better app.

Saying that, I truly believe that most users themselves do not know what they want.
We guys build a lot of apps and games and the approach that we take is to go through all our competitors reviews and make a list of mistakes they are making and try not to repeat them.

Also, I would probably put up the app before contacting people - as in my experience, when I have gone and asked people the "What do you want" question, I have mostly gotten weird, unrealistic feature requests. That is unless it is a consulting project for which they were paying.

So, I would first put up a small iteration of the app and contact people with a message like this:

Hi! I noticed that you are unhappy with so-and-so app. I have an App on the App Store 'link_here' which takes care of a number of issues that you have with the other one. I would love it if you can take my app for a spin and let me know your thoughts.

I guess that it is a good way. Because only when you ask your audience, you can get the really helpful feedback. Besides Google + you can use other social media. Facebook, LinkedIn, Q&A sites, forums. I think that you'll find right people who will help you with your app.