Apps App Signup & Inviting

[oo7ml]

Hi,

I am trying to understand three areas of App (iOS & Android) Development:

01 - User Signup
02 - Adding Friends
03 - Inviting Friends


01 - SIGNING UP
Am i right in saying that there are two ways in which most apps allow users to sign up:

A - sign up using your email address (like Facebook and Twitter etc)
B - sign up by using your unique phone number (like Whatsapp)

QUESTION 01: I understand how A works, but how does B actually work?



02 - ADDING FRIENDS (that are on the network)
When we join Facebook or Twitter etc we can add friends using one of the following three ways:
A - search for your friend (using their name) to see if they are already on the network
B - enter their email address to search for them

However, if we are on Whatapp we seem to be able to:
C - access your friends via your contacts (if they already on the app)

QUESTION 02: Again, i understand how A & B works but i'm still not sure how C works?



03 - INVITING FRIENDS (that are not already on the network)

QUESTION 03: what are the best ways to allow users to invite their friends to the app, from within the app?

Should they:

01 - enter their friend's email address
02 - enter their friend's mobile number

QUESTION 04: i presume it is possible to enter your friend's mobile number on the app which then sends a default SMS to your friends via the app, where by the sender pays for the text?



QUESTION 05: what is the easiest way to allow a user to sign up on and app and also invite their friends who are not already on the app?

Thanks in advance for your help.

 

[gerbyte]

My latest Android app (Buddy Locator) has them features. The way I did it was to register using email which gets encrypted and stored on a server. Once registered, the user can log in as usual using password as you would expect normally.
The user can then send a "buddy request" to another person using their unique registration number and all "links" get stored on the user's device to save online database calls and added security.
It doesn't do anything with phone numbers though - for this feature you would have to access the phonebook. Thi is what WhatsApp does, and marks those that already have/don't have accounts as appropriate.

 

[oo7ml]

Cool, thanks.

Do you develop in Android only?

 

[gerbyte]

Hi oo7ml.

I originally started on iPhone. I created an app and was really impressed with it!
However, I don't have an iPhone so I couldn't actually try it on a device. I had an Android device.
So from there I started on Android and worked with that ever since.
I am a professional software developer by trade, all mobile / web development is carried out in my spare time at home. I will also be starting on Windows phones but that will (probably) be later this year.

Thanks.