Best for expanding your network: WeChat
There are few options for expanding your network. You could try Meetups but those are for specific venues. Social media sites like Facebook and Linkedin specifically forbid adding contacts you don't know personally. There are dating apps but those are for, well, dating.WeChat works like other messenger apps, in fact it works quite well. The big difference is that it tries to expand your network with potential contacts who are nearby. You just have to shake your phone and you could find someone on WeChat who's also looking for a new friend. You can then add them or choose not to.
You can use the 'Friend Radar' to find friends who are nearby so you can meet up with them. When you do this a little 'radar' pops up on the app and searches for friends in your vicinity. Once you see them on your radar you can chat with them and propose a meeting.
https://play.google.com/store/apps/details?id=com.tencent.mm
Best for connecting with celebrities: KakaoTalk
KakaoTalk is easy to use but has many complex features. You have basic functions that perform really well and are quite simple. But if you want to get more out of those features, you can quickly dig in and find other ways to use them.There is a large network who use the feature 'Plus Friends' on KakaoTalk. This feature allows you to connect with people outside of your immediate network. These could be everyday messengers in your area who are sharing content or could be bands, celebrities, companies, etc.
When you add a friend through 'Plus Friends' you get to see their feed where they can share content. You can see what your favorite band is doing and find exclusive releases from them. If you're lucky, you can even chat 1-on-1 with a celebrity. There's a button for this next to their name. Give it a try, who knows, they might respond.
https://play.google.com/store/apps/details?id=com.kakao.talk
Best for contacts volume: Facebook Messenger
Facebook’s official instant messaging app has recently been made over to deliver a faster, cleaner service and interface. It’s much like WhatsApp (as are most of the apps on this list), but Messenger instantly connects to all of your Facebook contacts, making it one of the most convenient messaging apps, if nothing else.A recent update is that you can also message non-Facebook friends by using their phone number. Messenger allows you to access all of your Facebook messages without using the main app or website. It also has stickers and emojis, groups, voice recordings, location data, free calls, photo sharing and more.
Best for video calls: Skype
The granddaddy of video calls, Skype has been around for forever and is still kicking strong. Skype is primarily used for calls, but the IM component is just as useful. In fact, we use it as our primary communication tool here at AndroidPIT.Skype requires Skype IDs, so you’ll only be able to add friends if you know their Skype contact name. But once you do, you can send instant messages anytime you want, for free, as well as make video calls. You can also add Skype credit and make cheap international calls to landlines and mobile phones.
The chat section offers group chat, media sharing, emoji and more. Plus you can have one account on several devices (something that WhatsApp doesn’t allow).
https://play.google.com/store/apps/details?id=com.skype.raider
Best for secure messaging: Telegram
Speed and security are the name of the game for Telegram. The app provides encrypted cross-platform messaging and it's completely free.Founder Nikolai Durov stated that he set out to design a messenger that could not be accessed by Russian security agencies. When he offered a prize of US$200,000 to anyone who could crack the app's encryption protocol, no one managed it.
If you want a fast, free and secure messenger, Telegram comes highly recommended.
Best for exclusive features: Dasher
Dasher is making an effort to spice up the messenger market by employing some pretty cool and unusual features. It allows you to share GIFs and play YouTube videos directly in the chat window and there are rich URL previews: features that WhatsApp is only just starting to catch up with.One of Dasher's most unusual additions is that of being able to share money with your friends using Venmo, something that no other messenger provides – useful when you're lying in bed remembering how your friend bundled you into a taxi last night.
https://play.google.com/store/apps/details?id=im.dasher
Best for networking: Tango
It takes two to Tango, but there are plenty more than that using the service. Tango does much the same as the rest: instant messaging, media sharing, stickers, group chat, video calling, group chat, etc, but it also has a ton of extras. Tango recently went through a complete overhaul and now hosts a news feed and even dedicated news channels for you to follow.Tango will automatically find your friends based on your contact list, but they must be using the service to show up (or you can invite them). Additionally, Tango can be used to place calls, find like-minded friends or people in the vicinity using the service, which adds a bit more social networking to the mix than some other providers. The mid-call mini-games also help Tango stand out from the rest.
https://play.google.com/store/apps/details?id=com.sgiggle.production
Best for SMS: Google Hangouts
Google set up Hangouts as the standard (but interchangeable) messaging app in Android 4.4 KitKat, and thanks to this it picked up a lot more users. Hangouts is a combined SMS and IM app, that separates the two types of messages, but can be used to automatically place voice calls and video calls from your phone via Hangouts rather than traditional carriers.Because it handles both SMS and IM, it cuts down on the number of apps you need to be working with, and its video calling quality is arguably better than Skype's. In addition, Hangouts integrates with Google+ in much the same way that Facebook Messenger interacts with Facebook, meaning contacts added via the social network can be called or messaged in the separate app. Be careful who you connect with if you're a particularly private person.
https://play.google.com/store/apps/details?id=com.google.android.talk
Best for sticker enthusiasts: Viber
Viber is really pushing the sticker market, where you can get tons of free and paid sticker packs, but the core business of Viber is instant messages. You can also send recorded voice messages like WhatsApp (but not video calls like Skype) and you now have the option to call any phone number anywhere with Viber Out – much like adding Skype credit to call people who aren't on the service.
https://play.google.com/store/apps/details?id=com.viber.voip
Best up-and-coming messaging app: Line
Line is becoming more and more popular, and for good reason. With the recently added video calling functionality, it is now as fully featured as Skype, but has a younger, sexier feel to it than the tried and true Skype. It’s jam packed full of stickers and other fun stuff, and is immensely popular throughout large parts of Asia. But it’s also feature-filled with group chats, multi-platform capabilities (phone, tablet, PC), timeline, recorded voice messages, media sharing and much, much more, including official account messages from celebrities you like. Line is kind of like Twitter, Facebook and Skype all rolled into one.
Best for the office: BBM
After a substantial waiting period, BlackBerry's messaging service finally made it to the Android platform last year. BBM is not as Androidy as the rest of the apps on this list, but it does offer some very cool features including: always-on service (you don’t need to open the app to use it), timed and retractable messages, two-way opt-in (nobody can message you until you specifically allow them), delivery reporting, groups, emoticons, broadcast messages and more. The ability to choose who can message you, rather than it being available to anybody with your number, makes this an attractive messaging option.
Best for gamers: Razer Comms
Though Razer Comms is a fantastic instant messenger in its own right, it's first and foremost known for its popularity in the gaming community. With an accompanying PC version too, Razer Comms allows to you to group conversations, free VoIP chat, and it makes it quick and easy to connect with other gamers around the world. Think of it as Xfire for the smartphone era.
https://play.google.com/store/apps/details?id=com.razerzone.comms
Best for kicks: kik
"185 million people love Kik!" Says its Play Store description, proving there is more to messaging than just WhatsApp. Kik is a little more playful than the likes of WhatsApp, with more color and sticker options. Kik also houses its own built-in browser, to make video and image sharing between friends simple. It's a fast growing and friendly messenger with users from all over the planet. Give it a try.
https://play.google.com/store/apps/details?id=kik.android
Best all-around messaging app: WhatsApp
It's not all about WhatsApp... but WhatsApp sure is a big part of it. While it doesn’t have the same feature-rich content as many of the other apps on this list, WhatsApp can’t be beaten for simplicity, reliability, and the sheer number of contacts using it. Chances are, if you know someone with a smartphone, they’ve got WhatsApp.WhatsApp uses your existing contacts’ phone numbers, so you don’t need to add contacts manually. You can send written messages, stickers, emojis and media, as well as broadcast and group messages.
WhatsApp also allows you to make free calls to your contacts and now you can make Google Drive backups of your chats, too.
https://play.google.com/store/apps/details?id=com.whatsapp