Update: This post was written in 2009 and most of these apps are no longer around. I've recently written an updated post that gives you some good 2013 options. Here is Ten iPhone apps for IT.
When the iPhone App store was introduced, I was excited about the possibility to meet many of my IT duties without having to carry a laptop around. It took a little while to find and test all the applications, but I've finally put together seven applications that allow me to do all that I need to do here at Macminicolo. Perhaps they'll be of use to you.
Network Ping Lite - Free - iTunes link
The most common task I need to perform while on the road is make sure a server is up by sending a ping. Network Ping Lite makes that easy. Just enter an ip address or a url and it will send four quick pings and report. Alternatively, you can enter a subnet range and it will ping all the addresses. It does this quickly and you can watch the progress.
Network Ping Lite also allows you to perform a traceroute. This is beneficial if the ping doesn't return and you need to find where the problem is located.
And if that isn't enough, Network Ping Lite also allows for Telnet sessions. I've used it with both 3Com switches and Cisco Routers and it works great.
Finally, there is also a paid version for $4.99. This allows for storing up to 400 different ip numbers and domains. It also allows for telnet to other ports.
Web Tools - $1.99 - iTunes link
Web Tools is a nice way to work with domain names. You can enter any domain name (or ip address) and see the hostname, ip address, and ping results. It also gives you the geographical location where the domain is hosted with a link to the google map.
Web Tools is also a nice way to see if a domain name is available. In the WHOIS tab, just type the domain. The app will check all the different extensions (.com, .net, etc) and then report back on which are taken and which are available. If they are taken, you can see the WHOIS information including contact info, nameservers, etc.
Jaadu VNC - $24.99 - iTunes link
Jaadu VNC is a client to control your Mac or PC via VNC. It seems you can't mention Jaadu VNC without mentioning the price since $24.99 is much higher than the average iPhone app price. But price aside, Jaadu VNC has proven to be the most reliable and useable VNC app. The interface is clean and the connections are reliable and quick with refreshes. It's especially easy to use with a Mac since it supports the Leopard Screen Sharing.
If you just need the ability to connect and send mouse clicks, then there is a $4.99 version called Jaadu Click. (iTunes link)
iWOL - Wake On Lan - $4.99 - iTunes link
Every properly configured server should be set to never sleep. But when dealing with workstations there seems to be some sleep involoved. iWOL will allow you to wake a computer from sleep by sending a network message.
Those eco-friendly IT workers will appreciate the fact that you can put computers in standby mode and just wake them when needed.
iSSH - $4.99 - iTunes link
Of all the SSH clients in the iTunes App store, I found iSSH to be my favorite mostly due to the clean interface. It supports portrait and landscape mode. Also allows for you to store any number of connections so it's easy to jump between machines.
Netshare - $9.99 - currently unavailable
I hesitated including this app, but I'd be lying if I said I didn't use it all the time. Netshare allows for your laptop to use the 3G connection in your iPhone. Once setup, you can surf the internet from anywhere there is a phone signal.
This app has been pulled from the App Store because tethering isn't allowed with an AT&T contract. (Though other worldwide carriers do allow for it.) The reason I've included it is so others will be on the lookout if it returns. Also, there are other ways to get this app on your phone. Once jailbroken, visit your for favorite Mac torrent site.You can even send the developer a nice donation to quench your conscience.
GrandDialer - Free - iTunes link
GrandCentral is a service from Google that gives you a phone number and many options for forwarding and messaging. I know quite a few IT consultants who use this service to have a separate number for their business. It works great for incoming calls.
However, the problem arises when you need to call your customer from your mobile phone and would rather not have your personal number show up on their caller id. Also, you'd like them to recognize the business number so they knew who is callling.
GrandDialer is the cure for this problem. You can open the app and type in the number you want to reach. Once you hit "Call" then the Grandcentral will first call your phone. Once you answer, it will then call the number you want to reach. This will show your GrandCentral number on their caller ID. This app works great.
These are the 7 apps I use every day when dealing with the hundreds of Mac minis in our data center. If you know of any other apps that would be useful for IT folks, please let us know. We'd love to use them, and also share them with others.