Since its release in 2010, the iPad has sold tens of millions of units and has become a must-have device for both business and casual users. With its increasing market penetration, more and more specialized applications have become available for it. Many developers have written Commercial Real Estate App programs to specifically serve the market while other general purpose apps are especially helpful for commercial tenants. Here are five essential apps for commercial real estate tenants and professionals:

Loopnet

The Internet's leading commercial real estate marketplace has an app gives access to their database of properties for lease and for sale from anywhere. It opens up with a full-screen map that displays for-sale or for-lease listings. The app is free although if users with a paid LoopNet account get an expanded view of available properties in the market. While its value to brokers and to active tenants is usually obvious, it is also helpful as a tool for existing tenants and their real estate managers to keep an eye on the market around the property they occupy.

Dropbox

The Dropbox app works in conjunction with Dropbox on a computer to make files in a specific folder available anywhere. While it is not specifically a commercial real estate app, the ability to access files from anywhere is particularly useful for real estate managers that may need access to leases or expense data while they are off-site.

CoStar Go

CoStar's commercial real estate app is available only for subscribers of CoStar's full suite of products. It pulls sales comp data from CoStar Comps, property information from CoStar Property, tenant information from CoStar Tenant and for-sale information from CoStar Exchange to provide a unified view of the real estate market. Like the Loopnet commercial real estate app, it uses a map view, although it includes a number of additional features that allow its users to make detailed searches and even generate market research reports. It is an indispensable tool for anyone that already licenses CoStar and needs on-the-go access to information about the market.

PowerOne Finance Calculator

The PowerOne Finance Calculator is a $4.99 commercial real estate app that replaces traditional financial calculators like the HP 12C with a simple full screen interface that uses forms and templates. In addition to its built-in templates, other templates like a Lease Analysis tool, Sandwich Lease Option tool, and Property Analysis tool are all available to be downloaded for free. While PowerOne makes a number of different flavors of their Calculator, the Finance version is the most suitable to commercial real estate tenants and professionals.

SoundNote

Savvy commercial real estate tenants know the importance of keeping good notes from their meetings with landlords, vendors and property managers. SoundNote integrates three different types of note taking into one application -- offering the ability to type notes, write on the screen, or take audio recordings. It also keys audio recordings to notes, letting users click on a part of their notes to automatically skip to the corresponding part of the audio recording.