Apple store, trademarks and scraping

There are a couple of services in my country that provide a 'leads' directory to users, they ar both very popular and successful.

However, neither of them provide a mobile presence, and I believe this is a huge missed opportunity.

I am personally capable of developing an app that will aggregate (without hammering their servers...) leads from both sites according to their profiles and provide notifications/quick access, in a couple of weeks. Of course, this is all shady because i would have to scrape and cache ... And they may not be happy that I sort of lead users to their respective competitor.

Has anybody got experience with such a situation? Should I approach both businesses and see what they think? If I go ahead unilaterally, and they complain to apple, will my app get booted from the store (trademarks and all)?

Thanks.

I wondered whether to post this to the ios subreddit but decided I'd more likely find an answer here...sorry if its wrong!