Mobility in communications, was one of the most innovating thing that happened for humanity. The ability to stay connected and to share information with one another no matter where you are is empowering. And a big part of why it was successful, was design. The journey started with big bulky handsets that were super expensive and you could only get a few hours of talk time out of them, and that too if you were lucky. 

Then it moved on to feature phones, that were basically called bricks that while being slightly smaller in size, were still kinda bulky. There wasn't a lot of things that the user could do with them, though. But, these were priced lower and meant to be more affordable for the general public. Still not as affordable for everyone around the world, but it was getting there. Then came the turn of the smartphones. These phones were a breakthrough in terms of what they had to offer. 
Users could now pull up their organizer and schedule day, even add reminders and alarms to different tasks, apart from making just calls. These devices had other features to offer as well, but was mostly focused towards business people, with features included that'd help businesswomen and men make the most of their day with less effort. These devices again, didn't move all that much out of the conventional design style. Some devices adopted a hybrid style of including a touch sensitive screen along with a physical keyboard, others stuck to the keyboard but with the "qwerty" style. 
These devices gaining a lot of popularity, but it wasn't until Apple came out with it's iPhone range of devices, did the mobile phone scene radically change. With Apple's offering, the world over saw how the smartphone business could become the next big thing. This also meant another thing, the fact that the smartphone design had seen a major overhaul with Apple's decision to tally get rid of any physical keys except hardware controls for volume management, device sleep/shutdown as well as go to the home screen. 
And this has been the accepted (read popular) way to design smartphones now. And people aren't complaining, with Indian mobile developers getting hordes and hordes of messages to develop apps. But there are still manufacturers here and there that are still working on creating new designs in the hopes that one day people will look to that as the next big thing. The most recent revamps are smartphones with curved screens, where the curve is horizontal and rocking the phone to one side and the other lets the user perform different functions, for example give date/time information etc. 
LG's been in the news lately, after it said it was working on a smartphone screen that would be unbreakable, bendable and of course, curved. With wearables rapidly growing in popularity as well, will we soon see a world where individuality will be expressed not only by our lifestyle choices and the type of clothes you wear, but also through the electronic gadgets you use to go through the day. And this would undoubtedly make Indian mobile developers' lives a bit harder, because then they'd have to adapt their methodologies to develop their apps to adapt to real time changes seamlessly.