I dunno, wouldn't the better question be if I am at all comfortable using a third party app for financial transactions? Because I'm not. But I'm not super concerned about me, I'm curious how the thinking goes when someone decides to collect information about the loans that other people are taking out.
Maybe they are pretty sure that users understand it, the app could have a strong disclosure for all I know.
There is a rich ecosystem of LC apps and services because of LC's open API. The only thing the API's allow you to do is invest in loans and transfer money in and out of your account. I would be quite shocked if any service (such as lending robot) is able to operate without recording any transactions occurring. I hope users wouldn't be offended by the (very general) information revealed above, but I suppose some could.
Presumably LC itself is recording the transactions? It's obvious that apps would want to do so as well, but that certainly isn't a necessity. An app could remember a transaction long enough to ensure that it had posted, and then forget about it forever.
Primarily what I allude to in my initial comment, it indicates that they are in possession of specific user information. As I also point out above, I have no idea how informed the users would be about that.
I guess that might not meet all definitions of reasonable concerns.