By: Hillel Fuld

With over 300,000 apps for the iPhone, one of the biggest challenges that many companies are trying to overcome, is discovery. This is a challenge for the iPhone user who is overwhelmed by the vast selection of apps, but it is also becoming a serious problem for the developer who spends time and money developing an app, that more often than not, ends up falling into the black hole of the App Store.

The Masters of Discovery

This is where bloggers come in. There are of course many different ways to discover apps if you are a consumer, or to promote your app if you are a developer, but nothing beats personal review. I have already written a post about how to get your app discovered and downloaded, but based on questions I get regularly on Twitter (follow me here), many people who are just unwrapping their new iPhone are completely lost and overwhelmed when it comes to downloading their first iPhone apps.

On my iPhone and iPad, I have over 400 apps combined but I only use a handful of them on a regular basis so I thought I would share some of those with you. You will notice that there are no games in the list below and just so we are clear, that does not mean I do not play games on the iPhone. Despite my lack of interest in the gaming world and never having owned a gaming console, games on the iPhone are truly amazing. This list, however, are apps that enhance the iPhone and make it so much more than a phone in terms of its functionality.

The following are five apps I use regularly on my iPhone and I would recommend anyone download if they want to get the most out of their iOS device:

• Boxcar: One of my biggest concerns when replacing my BlackBerry with an iPhone was the email experience and specifically the delay in receiving emails. Thanks to Boxcar (Ultimate Notifier should get a mention here too as it was the runner up for best email notifications), there is no delay. In fact, I am pretty sure I get notifications about new emails on iPhone faster than I did on BlackBerry. Just to clarify, these are just notifications, the iPhone still has to download the message once I open the Mail app and in that way, BlackBerry still trumps iPhone. The developers of Boxcar release updates frequently and the app enables you to receive notifications about much more than new mail. Other services it supports include Facebook, Twitter, Google Voice, Foursquare, and many more. The app has a nice design and with the exception of one or two days over the last few months (on which they had server issues), it works flawlessly. FREE
• 360: There are some apps that I use regularly to show off the capabilities of the iPhone 4, 360 is one of those apps. It really is quite simple. Using 360 you can take a 3d image of your location and easily share it on your various social networks. The app is designed well with only one or two options to choose from. The result is a very impressive 360 degree photo, which is sure to amaze anyone when you tell them you took it from your phone. 360 is also one of the few apps I have seen that use the iPhone 4’s gyroscope effectively. $.99
• Instagram: This app has become an instant success and has gone completely viral. Instagram is basically a photo sharing network based on the iPhone app. You snap a picture or take one from your library, you enhance it with one of 14 filters, and you share it on the platform/s of your choice. The experience could not be simpler and the design of the app more intuitive. Right now, there is only an iPhone app with Android rumored to be on the way but there is no Web interface to browse Instagram photos. The network already has well over a million active users and I use Instagram multiple times throughout the day. The latest success for this app was that it was integrated into some big apps like Foursquare, which is a clear indication that it will not be slowing down soon. FREE
• Viber: Viber is another app that appeared out of nowhere and proceeded to go completely viral. Viber enables you to make free calls to other Viber users. The app is free and many people predict that if Skype does not get its act together on the mobile front, Viber will become a serious competitor. The latest news on that issue is that Skype is finally going to be enabling video chat on mobile, but I will believe it when I see it. Viber is designed to replace your iPhone’s Phone app with the ability to call Viber contacts for free or just make a regular GSM call through Viber. You also have the different tabs like in the Phone app: Favorites, Recents, and Keypad. The last tab in Viber is More, in which you can read about the company, invite friends, or promote the app on the social Web. Most importantly, the sound quality in Viber is leagues above Skype and it also, in my tests, uses less battery than Skype. FREE
• Tango: Tango is a hot one. If you use iPhone or Android, you can make video calls over 3g using Tango. This beats Facetime, which only works over Wifi and with other iPhone 4 users. In my experience, Tango is far from perfect when it comes to the experience and I had some issues adding contacts with whom I can Tango, but once I added them, the video call was pretty amazing. Tango has three main tabs, Contacts, Invite, and Settings. In order to add a contact, you need to have them in your phone address book with their complete phone number, country code and all. This caused some confusion, at least for me. To invite friends, you can send an email or SMS from within Tango but I am not sure I understand how that works since again, you need to have that person’s phone number in your address book for them to appear on your list of contacts. The Settings tab is empty with only the ability to fill out your profile and read tips. I would get rid of that tab and simplify the UI of Tango, but that is just me. FREE

When preparing this list, many apps came and went and these are the five I was left with. There are of course many thousands of apps that could have made this list and chances are, every app here has a direct competitor that offers the same functionality. That is what you are for. Please share your favorite iPhone apps below and spare us the Angry Birds, that is a given that goes without saying…

Honorable mentions: Camera+ ($.99), Kik (Free), IM+ Pro ($2.99), Dropbox (FREE), Bump (FREE), VLC (FREE), FLUD (FREE), Flyscreen (FREE), and Pulse (FREE).

So if the iPhone had a capacity of storing a total of five applications, what would they be for you?