Do not expect to find something that works with Google reviews since that would be considered incentivasation. Incentivising a review would be against the terms of service/use for Google Reviews.
From their own docs:
Reviews are most valuable when they’re honest and unbiased. For example, business owners shouldn't offer incentives to customers in exchange for reviews. Customers should always follow ourposting guidelines. You canrequest to remove a reviewif it’s inappropriate or violates our policies.
My memory on Yelp isn't as clear but I'm fairly certain they adopt a similar policy. Overall, rewarding someone for leaving a review doesn't lead to real reviews.