I'm sure there will be some muttering along the lines of, "Oh, geez, not another software list article". I tend to tune them out myself. The difference here is that I will be discussing applications that I use daily with my tablet.
File ManagerPossibly the most critical app in my kit is a file manager. I've used several since I first got an Android smartphone. I started with Astro File Manager from Metago, but I can no longer recommend it since the author seems to have abandoned it and will not respond to support emails. It works fine if you use Android 2.2 or lower; newer revisions have major compatibility issues that cause Astro to crash regularly.
I moved on to File Expert by Geeksoft. File Expert is a great app for file management, and has the ability to connect to a SMB-based network (Windows networking). This allows you to access your Windows file shares across the network and copy files to and from the server with your tablet. An added bonus is that File Expert also has a built-in FTP and HTTP server, so that you can access the tablet remotely.
File Expert does have some issues with running under Android 3.0 and higher. Recent revisions of the app will lock up the entire tablet requiring a hard reboot during any process that involves file copying or deleting. I have been working with the author to help get these issues resolved. He has been quite responsive to support and is willing to go the extra mile to fix bugs. Great service for a free app.
While I am waiting to help the author of File Expert to send me code to test, I have been using ES File Explorer from EStrongs. It is also an excellent, free file manager, with built-in SMB and FTP access. It's solid and stable, but the interface isn't as intuitive as File Expert. The clipboard is extraordinarily powerful, but it takes some figuring out. I definitely recommend it to Android 3.x users.
Security/AntivirusLet's face it, malware is going to be an issue no matter what platform you run. And there's also the problem of losing your device by negligence or theft. I went through a number of options before I discovered Lookout Mobile Security.
I cant say enough good things about Lookout. The free version comes with anti-malware scanning, contacts backup, and remote location of missing devices. The premium version adds a comprehensive privacy advisor, additional data backup, remote wipe and lock, and premier support, for $3 a month or $30 a year. It allows you to cover two devices, which is great for someone like me with an Android tablet and an Android smartphone.
Instant MessengerPretty much everyone with a smartphone and a computer uses instant messaging. Your preferred chat client may be AIM, or Yahoo, or Google Talk or Facebook chat. Many people like me have accounts on multiple chat services. For years I have been using the Trillian IM client from Cerulean Studios, and I'm a paid member of the premium service.
Good news for Adnroid users, however. Just recently they released a new version of Trillian for Android, and have made it a free app. It works perfectly with Android 1.6 to Android 3.1+, and covers a wide array of instant messenger services.
Office SuiteAny business professional that travels a lot is going to want an office suite. If you work with formatted documents, spreadsheets and presentations, carrying a tablet with an office suite instead of a laptop makes it a lot easier for a traveling professional.
I can really only recommend two apps for this category. The first is the old granddad of mobile office suites, Documents To Go by Dataviz. The most mature of the available office suites, it has excellent document compatibility with the Microsoft Office suite applications, and cloud access to Google Docs. The pro version retails for $14.99.
I also recommend Quickoffice Pro. While it does not have all of the document formatting capabilities that are in Documents To Go, it is still a solid, dependable application. It has a wide assortment of cloud access, including Google Docs, Dropbox, Box.net, SugarSync and mobile.me. It retails for only $7.99, which makes it a really good deal for the capabilities it provides.
BackupsNo toolkit would be complete without a comprehensive backup application. Fair warning: if you want to do a complete backup of your applications and data, you really need to consider rooting your device. Pretty much all of the available applications require root access.
There are numerous backup applications available, but the one that really strikes me as truly complete is Titanium Backup. Many times through my testing I have had to wipe and restore my android devices. Being able to do a complete backup of all of my installed apps plus the associated data has made the process a great deal easier--and I can take the backups and copy them to my server for safekeeping.
So what are YOUR must-have Android toolkit apps?