I tested a couple recently and chose Fossify Camera as the most usable. It’s pretty quick, takes decent pictures, and has a good interface.
Fossify is a group that has a number of very high quality apps that are generally as good or better than other open source alternatives.
A longer answer to those comments already here is that it may depend on the particular app. If you are trying to prevent the browser or a system app (including perhaps the app store or assistant, among others) from being opened, it may not be possible, depending on the exact OS you are using.
Most other apps can be prevented from opening links, as described in other comments.