Develop Reference

How to tell users about new updates?

I have a React Native app with firebase for backend,
And now I'm in the last part to release it,
But I have a question, after releasing my app I will add some updates or something and I want to ensure every user updates, so should I implement a modal that appears after adding some updates to my app and publishing it to stores
So I just thought if I made a boolean item if I add updates just change it to True and in my code if that true modal appeared else hidden it!
So that's a nice way to go with it?
Or can firebase help me in this case to tells any new things I do "I don't send to them push notifications if u want to tell me that"

If you want to tell your user about new update when they open the app, You can use Firebase Remote Config with needed keys like latestVersion, forceUpdate, releaseNotes, etc and show dialog in your app
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Demo Project

Is there any way we can update the link added to the app in webview dynamically without updating the app?

I've been working on an app which displays a list of websites when click on it will be redirected to webview in the app itself, I'm unable to find a way how to update the links dynamically without updating the app. So, If I want users to interact with new links the new links should automatically be updated in the app without update and in the webview too. Is it possible to do that?

You should use firebase remote config feature, which best fits in your case.
Firebase Remote Config is a cloud service that lets you change the
behavior and appearance of your app without requiring users to
download an app update.
Well to do that you first need to create a project in firebase console
In remote config feature you can add data in key-value pair. Like in this image:
I have added two key-value pair, as can add as much as you want. Now in the app side you have to add dependency:
implementation ‘com.google.firebase:firebase-config:11.8.0’
And to fetch the values which you have added in firebase, you can easily get those url but first you need to follow some steps to do that. You can check this simple tutorial.
Note: To get the values from firebase remote config you must need to click on publish changes button(Which you can see in above image top right corner).

You can store that link to a server and return that link when the app hits a certain API of that server. But for doing that, you need to setup a server, build a server application if you haven't already. Which is a lot of work for just storing a website link.
Another option could be, you can use services like http://bit . ly and create a custom link from that service, like http://bit . ly/my_specific_domain and use this link in your app. When you need to point to a different website, you can just update where http://bit . ly/my_specific_domain redirects to.
But you best bet would be to use Firebase Remote Config, which is both reliable and easy to implement, but that is already described in previous answer.

How can I change content of my app after it is published without updating version?

I want to make an android app that will display mess menu of hostel. The menu will be changing every week so how can I change content of TextView once it is installed in user's phone .I considered WebView but I want better alternative . I think I need some cloud based service here . What are some good resources to achieve this.

Just do a Simple REST API and then every time you start your app call your api to retrieve the information, for example
yourdomaing.com/api/menu/getmenus should retrieve a Json with every item on menu.
You have plenty languages for making a simple rest api
check this related link
Examples of REST APIS

You can store your data (Text/Media) on firebase,It is very easy to start and then enable firebase offline functionality so that it is not required to download data on each launch of application.
Update data on firebase and add valueEventListener in your activity to get that data.

An alternative could be Firebase (by Google).
It's a free and real-time service. It allows you to change the content while the app is running. See "real-time database" and "A/B testing" in Firebase.

i need to change topics in my app every day or every week automaticlly without the user updates the app

I have Christian Android App and there are 5 buttons in my app , I need to update the topics , news and Verses daily or weekly without let the user update the app , is there any way to do that ? I will be grateful if any one help me with tutorials , Please Guide Me THANKS

You can either prepare all possible buttons and choose which to display according to the current timestamp, or you need to build a web API that can provide you with the necessary data and is updatable independent from the app itself.

You must use webservice and SQL DB for this. If you want to add more information for user you just need to update your data base. And in each button tap you should call web api for getting the data.
For web service creation you can use retrofit.
Refer these links
http://www.vogella.com/tutorials/Retrofit/article.html
http://www.journaldev.com/13639/retrofit-android-example-tutorial
https://developer.android.com/training/basics/data-storage/databases.html

Perfect answer by Jacob you can also use cache along with the API call which expires after a specific period. So you don't have to force the user to go online every time he uses your app.

I would do this with notifications, you can have scripts that run weekly to change a topic... and on message receive you can update your topics based on the data coming from the "data-load" this is good because on top of that you can notify them "You have a new topic" or something like that.
There is a lot of resources to set up notifications, and if you are using android studio it is already built in.
https://firebase.google.com/docs/cloud-messaging/

Thanks all for helping me , i already solve my problem through Firebase Realtime Database Because of your posts , thanks again for your help
here is the tutorial https://www.youtube.com/watch?v=QETnC6SEwa0

What is most simple way to send notification of unexpected events to users of Android application?

For example I expect this kind of situation: data in my application lost relevance and so it usless until update. And until update it have to show users some predefined message.
Is here any simple and free solution to this task?
Guess I can use some server to somehow send simple messages... but it sounds way too complicated.
If this is important I use Xamarin.
Update: main difficulty here is fact - my application can't in any way define if it's outdated or not. This may happen in random moment.

Although the requirement is not very clear I assume Update here means app update.
each time user launches app make call to an api on ur server to check if user needs to update app
If that returns true take user to a static view that says app needs update and redirects user to google play to install updates

If you want to avoid using a server, you should try Firebase (https://firebase.google.com/). More specifically, you should use Firebase Remote Config (https://firebase.google.com/features/remote-config/).
Define in a key-value pair of something like minimum_app_version_required in Firebase Remote Config. Every time user opens the your app, compare the values of app version and minimum_app_version_required that you are getting from Firebase console and show a dialog box accordingly. You can also change the value of minimum_app_version_required anytime you want.

Just set some internal flag. That when that situation occurs, you can set the flag to true and just edit whatever layout element you are using such as listView or any other element with your predefined messages saved in strings.xml. You can also build any custom pop up screen, depends how you want to show them. Let me know if you didn't understand or exactly how you want?

Need to implement versioning for this problem. To achieve this, you have to maintain a version number in server, this is the version number you app will have to save and use it to validate with server. If both are not same, then app will get the latest data from the server.