Until now there was no way to share an entry with some else. This is still the default-behavior! But if you like to share some of your entries with friends and family, you can activate this in your advanced settings. It's called Share single entries via link.
Then you find a "share"-link if you open a day-view of any entry. Clicking on this link opens a selectbox where you choose the expiration of the link. You can create several links with different expiration-dates. To get the link, click on the button "create a link for". Then a textbox appears from which you can copy the link to send it via email or whatever to your friends and family.
The recipient can only see this one entry and nothing more. They will not have any access to your other entries or your saved values.
If you have sent a link to someone and then deactivate the share-feature, noone can use the links any more and all your public links will be deleted. So, if you are not sure what links are out there you can delete all of them by deactivating the feature and activating it again.