One of the greatest indicators of whether or not I end up being a long time user of certain piece of software is PERSISTENCE.  Is this piece of software accessible everywhere I want to be?

These are the places I spend my time, and these are the places I need to access my apps

1. web
2. mobile (apps & web apps)
3. desktop
4. email

Example 1: Evernote

They’ve got a web app, an iphone app, a blackberry app, a bookmarklet to clip content from the browser (firefox & safari), and desktop apps for mac and windows.  They are covered from almost every angle, and for those moments in between I can still send in notes via email.

Example 2: Posterous

For Posterous, publishing directly from their web app was almost an after thought.  They know its a lot to ask to require someone to come to your site just to create content, so their main focus is e-mail.  E-mail is a shortcut to accessibility, and saves them the time and effort of creating apps for different platforms (even though they have a great iphone app for posting pics)

I can create posts from Gmail, or from my mobile phone, and then I have the option to send these posts to any of the services that you see in the list here on the right.  You can set it up to auto post for to every service in your list, or you can choose on the fly by indicating the destination in the email address you use ” flickr+twitter+vimeo@xxxx.posterous.com” or “posterous+flickr@xxxx.posterous.com”.

Not only is Posterous accessible from almost anywhere, but it actually increase your reach by tying into all these extra services.

Example 3: Remember The Milk

RTM ( Remember the Milk) is a todo or task application, and what makes it so great is that I have access from anywhere.  Not only can I view my todos from their iphone app, mobile web app, web app, and even a few 3rd party desktop apps, but I can also add tasks via email.

No matter where I go, I know I can quickly jott (yes, they integrate with jott too, so you can create tasks via voicemail) down reminders to do things, or look at my list of todos, which is what makes RTM so sticky.  If i needed to jot something down, and i wasn’t able to get access to the app, that would be the first step in making me into a non-user.

So how are you making your apps accessible from everywhere?  Is this tough to do with a small team because of the resources required to build for so many platforms?