There is a nice Rating Button Within PowerApps, within Sharepoint as well, please let them communicate with each other!
E.G. if a make a rating within Powerapps, please store it within the Rating Column of Sharepoint.
For more Infos, have a view as well within this discussion:
Besides the Raring with stars, also inclide the "Likes Botton", it would be great people can vote with power apps. Thanks!