The claim that Freeway is rising in the US rankings is misinformation.
Similar web is not an official application store, it is a market intelligence provider and has no affiliation with the Google Play store or The Apple App Store. The rank they provide is their own opinion using their own data and therefore, unsubstantiated. To put the ranking inaccuracy into context; the google play store doesn't even register the freeway app in the Lifestyle top 500 however, Similar web places it in at #245.
Moreover, the 'usage rank' that similarweb uses, is an impossible data set to gather for a third party. Only the application developer has access to their application usage data via their own servers. I am positive that Syntonic do not allow similarweb access to their usage data.
To make matters worse, the graph you have referenced is SimilarWeb's Usage Rank vs Google Play Rank. However, this Google Play data is not available on their site. Similarweb either don't have the Google play store data or it is coming soon, as they claim. Therefore, the data represented is only Similarweb's vs nothing.
The screenshot in the above post has been cut down, so allow me to post the full picture:
It is ok to say that Freeway is rising the Similarweb Rankings but not anywhere else.