THOSE who bought an iPhone 4 after it debuted on the Chinese mainland in September can now enjoy a range of applications they have been waiting for and put them to good use during the upcoming Spring Festival holiday.

Based on iPhone and its online App Store, users can download various applications, such as games, entertainment, social functions and photography.

Users can send out hundreds of free short message service greetings, including pictures and video messages.

Tourists and people returning to their hometowns can check flight and rail information directly on their iPhone handset client, including how many peak rail tickets are available. For tourists going overseas, Lonely Planet handset client is available on the iPhone.

Casual games, miniblog or weibo, picture-sharing websites and high-definition video calls are other options.

Of course, users can also download applications on the latest Android and Nokia phones but the App Store has 300,000 applications, by far the most and for each function, there are multiple choices.

Most iPhone applications can be operated on iPad and iPod Touch.

In addition, applications can also be used after the festival. Most were popular apps in China in 2010, the first year of the booming app market.

WhatsApp Messenger

This chat app is perfect for Chinese people, especially during Spring Festival, when they send greetings covering almost all their phone contacts.

Installing this app saves a lot of money on message charges through carriers.

Much like the texting app that comes on the iPhone, WhatsApp Messenger shows chats in little text bubbles, adds a time stamp on messages and lets users include photos, audio notes and videos within conversations. Users can send their GPS location on an interactive map, making it easy to find the distance between friends and how to get to them.

All functions are based on Internet with WiFi or cellular networks, so they are almost free. For China Mobile's package, each short message costs 0.1 yuan (1 US cent) and a multimedia message (photos and audio) costs about 0.5 to 1 yuan each.

It will automatically detect contacts using it, without any registration. I have already added several dozen contacts and add one or two daily.

Price: 99 US cents

Function: Social networking

Also recommended: Kik messenger (free) and Weixin (free)

Jiepang

Jiepang is one of China's most popular location-based services (LBS). It combines information and entertainment through mobile networks that pinpoint the geographical position of a mobile device. It can not only identify a person's location, but also help find other locations, such as a cash machine or the whereabouts of a friend or colleague.

Lou Ying, a 29-year-old financial auditor, is addicted to "checking in" online, using her mobile phone to tell friends where she is and what she is doing; this tracks her movements whenever she moves, from home to Metro stations and even to guest houses where she stayed during a New Year holiday in Thailand.

Users can share pictures and comments through Jiepang, which can be synchronized with popular social websites including Sina weibo, Kaixin001.com and Renren.com.

Price: Free

Function: Social networking

Also recommended: Foursquare (free) and Qieke (free)

FaceTime

Those separated from family and friends can stay in touch through high-quality video calling, using FaceTime, an iPhone 4 built-in feature.

With a tap, people can wave hello to their children, share a smile across the globe or watch a friend laugh at their stories. It allows switching between back and front cameras.

It's the best tool I have tested for video communications but it has high requirements - iPhone 4 to iPhone 4 or to the new iPod touch over WiFi networks. (Users can use FaceTime through Mac computers but it has a wide choice for video call communications on the computer client end).

The other choice is Skype, which provides okay quality, but it supports almost all smart phones, including iPhone, Android and Nokia.

Price: Free

Function: Communications

Also recommended: Skype (free)

Instagram

During the festival, people take pictures all the time and the iPhone 4 offers surprising photography applications.

Instagram is one of the top 10 Apple photography apps for 2010. It provides special effects on photos and creates a picture-sharing community.

Users can snap photos wherever they go and show the world; follow friends' photo updates as they move around;and choose photo filters transforming regular photos into artistic works.

It supports Lomo, Nashville, Apollo and Poprocket.

I also recommend a paid application, Panoramatic 360 for 360-degree photography.

Price: Free

Function: Photography

Also recommended: Panoramatic 360 (US$1.99), PS Express (free)

Sina weibo

Though Twitter is not available on the mainland, a similar microblog service called weibo is spreading like wildfire.

The most popular is Sina weibo, which tells people what's not in official media and lets them share during the Spring Festival.

Users can upload a posting of 140 words. It has attracted numerous celebrities. By late 2010, China's microblog user base was estimated at 65 million and by June this year it's expected to surpass 100 million. This mean one of four or five Chinese Internet users will use the services, according to Sina.

Sina provides weibo HD for iPad users in high definition and better display.

Price: Free

Function: Social networking

Also recommended: Kaixin (free) and Tencent weibo (free)

Qunar

'Qunar' means "where to go?" and provides free travel information on flights, rail, hotel and other transport and destinations.

Since it's free, it provides promotions such as discount fares and phone numbers, which can be useful. The most interesting aspect is its real-time status checking system, which reports each flight's status: arrived, departed, on time, delayed, canceled. People can check before going to the airport. Rail passengers can search the route they want based on price, day and time, train type and departure station. For example, passengers can choose which of Shanghai's three rail terminals to use.

Besides Qunar, other applications provide destination information. Lonely Planet's apps puts the tourism guidebook into the phone, including LP London and LP Paris.

Domestic tourism magazine The World Traveler launched its latest 100-page Bangkok guide in the App Store, its first digital publishing on the store.

Price: Free

Function: Travel

Also recommended: Ctrip (free), Lonely Planet (US$5.99 for each country or city) and The World Traveler (US$3.99)

Other popular applications are useful during ordinary times, as well as holidays and festivals. They include Zake (free) on iPad for customized reading, which is very like Flipboard. For Groupon, it has many Chinese counterparts, such as Meituan and Lashou through a guide application Tuan Gou Hui, which collects and displays discounted information together. For gourmets, Dianping (free) with restaurant reviews is useful. For game lovers, there's Angry Birds (99 US cents). For multiplayers, there's Marble Mixer (99 US cents).