Develop Reference

Android Application Permissions Logging

i have a question related to Android app run time permissions.
Is it preferrable/allowed practice for developers to save users' permission preferences i.e. each user has allowed/denied any permission, on our remote server database?
Offcourse we are asking run time permission for every feature we want to use, but is it preferrable that we log on server that if user has allowed for any permission or not, please let know. Thanks

Android framework has restricted the developers to ask only those permissions which are necessary to implement a specific feature and that too if there's no other way to implement the feature without that specific permission. In your case, it seems like you have already taken care of the permissions and just want to hold the result of the asked permissions.
So the answer is YES, You can save this data and it's even considered good practice for handling permissions. Here's the reference from the official android documentation.
Greater flexibility in granting permissions
Users can deny access to individual permissions at the time they’re requested and in settings, but they may still be surprised when functionality is broken as a result. It’s a good idea to monitor how many users are denying permissions (e.g. using Google Analytics) so that you can either refactor your app to avoid depending on that permission or provide a better explanation of why you need the permission for your app to work properly. You should also make sure that your app handles exceptions when users deny permission requests or toggle off permissions in settings.
https://developer.android.com/training/permissions/usage-notes

Android Permissions should be asked on startup or only when needed?

I have built an app that use different kind of permissions like location, contacts etc.
Not all the permissions are used by all the users, instead each user only needs the permissions related to the features he/she is using it.
My question, should I ask all the permission on startup for all users or can I add them gradually while using the app and only when needed?
Thanks

If a user doesn't know why they need to accept a specific permisson, they may be suspicious and refuse (eg. camera).
If they click on a functionnality like 'Scan code' they will know why they are being asked for that permission and accept.
If you asked beforehand and the user refused, when you get to the part where you need that permission, it won't work. This is why they changed it to dynamic permissions in Android 6.

Android M: Effect of Selective Permissions on Ads

Now that Android 6.0 becomes more popular among users, I've asked myself what the consequences of the selective permission granting are.
Let's assume I had a free ad-supported version of an app. It will obviously need internet permission to query ads. Now the user is able to deny that permission and apps could not be queried. The consequence I am thinking of is to deny app function if not all the permissions are granted. But this would make the permission model pointless for my app. It would be an "all or nothing" scenario. Is that thinking correct? I am interested in your thoughts.
Another thought I had was: Is the permission of internet access granted to AdMob automatically, by any chance? This would prevent users from disablings ads simply by takingvaway the internet permission. As AdMob is a Google company and this functionality is implemented in the Google Play Services, I guess that could be possible?! Any thoughts on this?
Let me know what you think.
Update: Admob also wants to have Location Info. So even though Internet does not need permission, the question still is interesting.

#mad: in android 6.0, your app never ask your to allow internet permission. because internet not part of user's privacy in android 6.0
(in sort user not able to deny internet permission) only on/off internet from device!
so don't worry about it. you app work same in android 6.0 as previous version of android.
you have to ask user for permission only if you are using, CAMERA, CONTACTS, LOCATION, MICROPHONE, Phone, STORAGE ...etc..
LOCATION: when you fetch location from your app and pass to any 3rd party app. in this case you must have to ask user to allow location permission. otherwise its not needed like Google Play service or In-App Purchease.(both fetch user location where app installed or product purchase but when we use both library in our app we must not have to ask location permission).

How to Hide the Android Manifest Permissions

is there any way for hide the android manifest Permissions for some reasons and user couldnt see during installing the app?

Taken from the support page from Google Play:
Google Play shows you which permission groups an app will be able to
access. This information can help you decide whether you want to
install the app.
The whole sole purpose of those permissions is for people to see what your app can access and decide whether they want to share (all) that information with you.

In Android L and lower, this is impossible. If you do not ask for a permission, you will get a crash when you try to access the thing that needs permission. Thus, you cannot hide permissions from users.
In Android M, the whole permission idea is changed: instead of asking for lots of permission at the install, the app is installed without permissions, and when you need a specific permission, for example for camera, the user will have the option of accepting or declining the permission. Thus, the user will have a clearer view of what a permission is asked for.

How to grant permission dynamically in android, i.e while running an application, Is this achievable?

I have few doubts.
Is it possible for Android application after installation, to ask user for permission for accessing certain functions? Like say the app A wants to read contacts for a specific purpose. If the user grants permission, then the activity will take place. Else it wont. Is it possible?
Is there a way of allowing user to select/de-select permissions during installation time?
I have read that using CyanogenMod grants user these kind of priveleges. Is there any solution for non-rooted user, apart from take-it-or-leave-it approach?

It would be great, but not, all permission must be granted during installation :-(
Only exception is access to the google profile, this will be authorized during first access.
I hope that a future android version will can do that.
Cyanogen can do opposite. You must grant all permissions during install, but you can explicitly remove them later. But it result in application crash very often. This is only for advanced users.