Hey Patrick,
There are two issues here:
1) For the topo search, you are correct - we fell out of the top few places, because Apple made us change out name. We used to include a bunch of keywords in the title, including topo maps.
Unfortunately, they are still letting our competitors do this, presumably until they next release an update for their apps. This is affecting our sales a little bit, and I've complained to Apple several times, but they brush me off.
My plan is to include the words "topo maps" in the title in the next release, but not the other long list of keywords. The topo search is the most important one.
2) As for reviews, each new release, your app's old reviews don't show up, unless the user clicks some buttons. Your star-ranking that is visible is based on your current release, once you have at least 5 reviews.
Users are allowed to update their reviews, which bumps them to the top of the list.
Because of this weird review setup, developers need to get reviews for each new release. I think most of the top apps do it with an in-app prompt - which we use too, but it doesn't trigger on each release for us.
Andrew