Hookle makes it simple to respond to comments and reviews without opening each social media app separately.

Simply open the post and click Show post in the post details view (1). You can now see and respond to comments and reviews (2) of each account from a single place.
Note, that you need to have the Google My Business app installed on your phone to be able to respond to comments from your customers on Google. Install it from Apple Store or Google Play.
Note, that you need to be logged into the specific social network or Google to be able to see and respond to comments and reviews.