Yes, there are some limitations on what you can do with the free tier of Redirekt. Specifically, you can only have 10 items across your Library and Reading List at any point in time.
We believe this is a fair number of items for people that are just casually saving links in Redirekt. This number also allows us to maintain your data on the Redirekt Cloud safely without incurring in unexpected costs.
At the moment, there are no feature limitations on Redirekt Free. You can use all the available features, but you are limited on the amount of items you can add. This may change in the future, as we may decide to introduce new features that are only available to users of Redirekt Pro. We will never remove existing features that are currently available to all users to offer them to Redirekt Pro users only.
Also, please note that, even if you're not paying for Redirekt Pro, your data is stored using the same systems as Redirekt Pro users. This means that your data is always safe and available on all your devices.