Develop Reference

How can an age restriction be applied to an Android app?

I'm working on an Android app where a user must be 18 years or older to apply.
If there will be people under 18, the app would have negative public view which I do not want to deal with.
Is it somehow possible to be sure that my users are older than 17? Is there any service which could possibly accomplish this?
Ideal fictional solution: in my registration form the user writes his/her id number and I would check if he/she is old enough with fictional service.
One not very good solution which I found. There is an app called Muzmatch. It is dating app for Arabs. When the user register he have to use device camera to take picture of himself and send it to server.
I can do the same in my app and check if the user seems old enough but I think it's stupid idea.

Yes this is possible through the Google Play content rating system.
Check out the link: https://support.google.com/googleplay/android-developer/answer/188189?hl=en-GB
Scroll down to the Take your app’s rating questionnaire section and it'll run you through the steps to apply an age rating to your app.
In addition to this, maybe you could create a free in app purchase, that the user will have to buy when first entering the app. They would then need either a password or finger print in order to pay via Google Play.

Is tracking individual user behavior possible in Google Analytics Premium for Android app?

Is Tracking of user Behavior like which activity user saw, what time he saw them , and all possible. Or Can this only be done from the back end ?
Does Google Analytic Premium has this feature ?
Edit:
We are looking to track the user behavior on android application and want to know the details of the pages the user has visited within the app.
The Google Analytics gives me the count of the visits however it does not confirm as to who visited which page. The user_id tracking for Google Analytics is not working for some reasons.
Is there a tool where we can record the user behavior to eventually improve the app functionality.

If you want to track individual users, you need to send a unique userId to google analytics as a custom dimension value. Make sure the Id you send to google is not PII as that is against google's privacy policy. You don't need to have a premium account to implement this behavior.
If you are not aware of how custom dimensions work, please check this link for more info on it
https://support.google.com/analytics/answer/2709828?hl=en
Also for things like at what time a particular user viewed a page, you can look at generating Custom Reports. Select Parameter Time from Dimensions Tab in Custom Reports. More info here.
https://support.google.com/analytics/answer/1151300?hl=en

Has anyone gotten Google Play's "Tracked Channels (UTM)" campaign tracking to work?

The Google Play Developer Console offers the Tracked Channels (UTM) view under User Acquisition → Performance which should be able to show a breakdown of which tagged links users clicked to get to the store listing, etc.
I have generated several different links to my app using the Google Play URL Builder, e.g.:
https://play.google.com/store/apps/details?id=com.vandenmars.colortrek&referrer=utm_source%3Dso%26utm_medium%3Dlink%26utm_campaign%3Dlink%26utm_content%3DTBk
I did a couple of tests last week where I opened the Play Store using these links and installed the app on new devices immediately from there. Still, the Tracked Channels (UTM) list shows no entries.
A bit more background that may be relevant:
My app itself does not use the Google Analytics SDK and does not register a receiver for the INSTALL_REFERRER intentI would assume that the Play Store handles the links directly without requiring app interaction, especially since it can track store listing views that don't lead to installs, but maybe this is incorrect? Or maybe the store disables tracking based on the app manifest?
I opened the links in Chrome on my PC and clicked "Install" thereMaybe the links only get tracked if they are opened in the Play Store App on the actual device? Seems strange, but I am running a test on that right now, the data just hasn't updated yet.
The tagged installations I did were on days that have been processed alreadyIt sometimes takes Google a long time to update the "Performance" data, but the data I can see already includes this Sunday and the tests were done on Friday. So, unless the UTM tracking data takes even longer to get processed, it should already show up.
Do I need to enable something somewhere for this to work? Or am I doing something else wrong?
UPDATE 1:
Meanwhile, one entry has started showing up in the Tracked Channels (UTM) list. Unfortunately, as the help-text states, "UTM-tagged links that have a single store listing visitor [...] are included in the “Other” category." So I have no idea which of my test links it is, if any. The entry is only showing as a Store Listing Visitor, but not as an Installer.
The last day included in the stats is Wednesday (supposedly), which is also the day when I did the test of opening the link directly in the Play Store app on a device for the first time. I did install the app during that visit, but it was after I had uninstalled a previous installation.
So, here's what I learned from this:
It doesn't look like there is some on/off switch for UTM tagging that I need to enable.
Including the Analytics SDK and registering an INSTALL_REFERRER is not strictly needed for just the tracking of Store Listing Visitors, but it might be needed to track Installers/Buyers.
There may be a difference between visits to tagged links from a PC vs. from the Play Store app on a device.
This leaves the following questions:
Are UTM links only tracked by the Play Store app, or also by visits to http://play.google.com/...?
Does an app need to use the Analytics SDK to forward information about installs and purchases to the Play Store, or do these get tracked independently of the app like the store listing visitors?
Is only the first installation of an app on a specific device counted under Installers, or is a fresh install after an uninstall also counted? How about after a factory reset of the device?
Bonus question: Is there a way to expand the "Other" category? :)
UPDATE 2:
Now I'm back to square one: 3 days ago, I opened more test-links on different devices (including the one that I thought was the one that showed up last time), directly in the app store, installing the app immediately. The data shown includes everything up to and including two days ago, so these visits and installs should be tracked by now. Yet, the list does not show any additional entries beyond the one from update 1 above.
So, either I have absolutely no clue what should be going on, or this whole tracking system is one giant buggy mess... Some things I've read in random forums suggest the latter, but maybe I am missing something, too?
UPDATE 3:
This is getting stranger and stranger. Now, all of a sudden, I see an entry showing 14 store visits and 10 installs for "zedge/android"! Why would someone make their own utm tagged link for my app?!? On top of that, none of my other tests have ever shown up (still just the original entry under "Other") and I don't even see the 10 installs in the statistics... Looks like this whole thing is just plain broken... Correction welcome.

We're in the same situation too now. No Google Analytics set up, need to run some ads this weekend, so I'm going to try to use UTM tags to track the app installs.
There may be a difference between visits to tagged links from a PC vs.
from the Play Store app on a device.
Found this in their documentation
"Note: Over-the-air and web (play.google.com) impressions aren’t
tracked on your app’s User Acquisition page at this time."
If you want, send the link over and I can test it out.

Before direct user to Google Play app page, send GET request with UTM params to your own site. Register this site to Google Analitics. It will count page visits only.

I am going through the same problem. I wanted to test if the UTM source and UTM campaign from the new Dashboard required some SDK or API installed in the app itself. So I contacted Google Play Devs, I asked specifically if we needed Google Analytics and their response was:
this not the case and also there is nothing further that you can add to the app itself.
I did try downloading my own app and sent the link over to a couple of dozen people (bare in mind that the app does have a Google Analytics setup, but it is from 2016, so old version) with the following link
Power my Robot with UTM links setup
I put random words, and all the visits and downloads on both UTM Campaign and UTM Source showed under "Other" and not the words I put. I managed to get around 20 downloads from this link.
However, after questioning Google why it was showing under "Other" and not the word I put in the link, they said it is because of a minimum threshold, which they don't know the amount.
As mentioned above, I used this form to get the Google Play with the UTM tags.
And also, I agree with a comment above, that Apple simply works. From the campaign section in the dashboard, you can open the "Link Generator" and they specifically say that the minimum amount in order to show the number is at least 5 installs using the link in order to protect users' privacy. Google Play can learn something from Apple in this case.
I will try to keep this updated if anything changes on my stats. And feel free to click on the link above and install the app, open and then de-install, just to build up the numbers and see if I can cross the threshold and discover what is the minimum amount they require.

I confirm that the Google Play Store UTM tracking doesn't work with your configuration, as I have the same (no Google Analytics SDK, but firebase-core) and I can't see any installation listed in the Acquisition view of the Play Store.
I note that the Play Store documentation part about UTM tag has a link to an url builder on the Google Analytics Guide, so may be the solution in to install GA SDK.

Have found google page that suggest how to build url with utms: https://developers.google.com/analytics/devguides/collection/android/v4/campaigns?hl=es#google-play-url-builder
This is an example:
https://play.google.com/store/apps/details?id={application_id}&referrer=utm_source%3D{source_id}%26utm_medium%3D{medium}%26utm_term%3D{term}

Does Google Play Store provide any mechanism for app activation

I need to be able to prevent the user from using my app until I allow him. The idea is that the app should be available for download but the user should only see activation screen when he launches it.
Then he has to request an activation key through email and use that key to unlock the app.
Is there a way to achieve something like this in Play Store and is it allowed?
I also don't like this idea but its my client's wish..
Note to moderators: I posted a similar question for the Apple Store but I want to keep both threads separated so please don't consider this as spam.

Google Play does not have such a feature out of the box.
I can however, think of 3 ways you can get it work. I am speaking strictly for the Android platform though.
You can design you app in such a way that the first screen should ask the user to get an Activation Code / Enter an Activation Code.
After the above, you can either store the Activation Code in a Preference File and check the value for its validity and start the application only if it matches / is valid.
Store the Activation Code in a Database and again, check the value and its validity and start the app if it matches / is valid.
Provide a couple of features and integrate Google Play In-app Billing and let the user pay a one-time fee to activate and enable all functions in the app.
These are the things I can think of at the top of my mind. Hope this helps.

No, There's no way to achieve this. You will have to create a functionality within your application.What you can do is make the user enter an activation key, if the activation key is correct make the user go to the next screen else don't let the user.

Thats something you would have to implement in your app. If there is some payment involved in getting the registration key then the solution is clearly against the play store rules.

i use similar system on my application. When user open the app first time. I ask for promotion code if this promoition code is true (i check it from back end service) user can use app for 3 months free. After this period end, app ask user to buy subsciription. You can do it using a backend service with interact a database.

Can I track what keywords lead users to find my app on Google Play?

I know I can add a referrer parameter to the Google Play URL to track downloads from a specific source, but can I track which keyword searches users used to find my app on Google Play?

Before Google Play, i.e Android Market, I was receiving in the referrer all the relevant information to help me understood how my app was found.
It could have been keywords, tops, similar applications, etc.
It was really, really useful.
Since Google Play, I do not receive anything anymore. The only referrers I get are the one I set manualy when I do some campaigns. I spent a lot of time trying to understand why, but it looks like Google Play just doesn't send this information anymore. Doesn't make sense to me, however.
However, you'll get keywords of how users found your application on Google Play from Google search engine (if they hit "Install on my phone" button).
Referrer example utm_source=google&utm_medium=organic&utm_term=my+keyword
(doesn't work if user is using https Google search)

Not exactly, because your app is found by keywords defined by YOU.
-> If you're selling navigation based app, you may enter "navigation". Therefore it appears under keyword navigation and in that case, the result would be relevant.
If they open something related to app that is related to your app, will you be interested in the first keyword that could have been something totally different?
-> If there's an app with keyword "children", they open it and Google Play then recommends something else with children, they open it. Then, this second app, having also keyword children could have a tag "navigation". Then Google Play could recommend YOUR app. I don't believe that tag "children" would be your concern :-)