Requiring User Login for Mobile App

I am working on a series of utility mobile apps whittle residential real estate investors manage their businesses. The apps I am developing are highly specialized and impactful. I plan on making them fremium in that the users can try the apps for free but must pay to unlock the key functionality.

I would like to hear people's opinions on the usability of requiring a user to register for an account for a mobile app, either through email/password or Facebook login, in order to use it.

I will be using the user account to provide cross device sync to the users. I am wondering if that by requiring a login, some users will decide not to try out the app due to the extra effort and/or privacy concerns associated with registration.

Requiring a logged in account to edit information will greatly simplify the development process.