Xamarin

Xamarin is well suited for mobile app development. It's nice to share almost all of our code between Apple and Android as well as between phones and tablets. We have our own PC tool, I don't use it for PC or Mac development but would like to go there with some shared code at some point.

If you are required to develop applications that are cross-platformed, Xamarin is a great tool to use. It will help save time and effort from your development team to be able to build applications seamlessly for android, IOS, Windows, and web on a single platform instead of requiring multiple tools to get the job done.

Xamarin comes in handy when you want to write cross-platform (for Android and iOS) applications without the need to code twice. It shortens development time and that's an advantage. Xamarin also helps developers building on .NET transition to mobile development without the need to learn additional programming languages- saves money and training time. Most of the time Xamarin is all good a part from a few times when you want to keep up with new features and Xamarin takes time to implement them.

Xamarin is perfect if you have senior .Net developers and do not want to have write code twice. Once for Android and once for IOS. This also allows you to have one code base platform that make changes much simpler and keeping both versions in sync. It would be nice if you could have some common settings files across the 2 that would inject into the pList file for example.

Xamarin is perfect for business apps. Developing games is probably better in native code. (But I have never developed games with xamarin.)

Great for line of business applications. Not so great for cross-platform games (use something like Unity instead).

Business application its the best bet. For game-like applications, it may not be the best bet.

Xamarin is definitely the best product to use for C# .NET programming on MacOS; for other uses it may not be the best IDE: different languages, different platforms, etc.

I've introduced Xamarin to multiple organizations. Unless you have engineers who insist on not knowing C#, there are rarely any instances where it's not the best choice.

Xamarin is well suited for several reasons. The first, it allows companies to share code across platforms. If the app has a lot of business logic and a fairly simple UI, Xamarin is great for this use case. Xamarin also works well if the developers who will work on the app are already fluent in .NET.
Xamarin is less appropriate if the company has a lot of developers. If there are plenty of resources to develop apps natively then the headache of dealing with Xamarin's issues are not worth the effort. If the UI is very complex and has difficult animations it's difficult to debug visual/performance issues in Xamarin.

Xamarin is great for any scenario, even if you don't utilize Xamarin Forms, which is the code sharing capability. But even if you just utilized the platform specific code, it's still all in C#. Makes it easy to not only maintain, but later hire developers who might not have any Xamarin experience to be able to come on board quickly and make an effect.

It is well suited when you have a single codebase, tight deadlines for the product release, and you have less developers to tackle the problems that can occur in testing and release level. It is less appropriate in situations where you want apps like system-level tasks which may not be allowed by Xamarin