Here is how I currently manage caching in a project and limit it to being refreshed once every hour:

In My App.Config I set up a static variable:

public static String CacheOffset = "?Cache=" + ;
System.DateTime.Now.DayOfYear.ToString() + ;
System.DateTime.Now.Hour.ToString();

When I populate my local collection I then use something like:

String MyImagePath=”MyBitMapImage.png”+App.CacheOffset;

This way the images are cached for the duration of the users WinRT session and also up to an hour beyond the initial population of my data collection.   Obviously I can vary this duration using different parameters from the current system date and time.  For instance the following would ensure that effectively no caching is carried out between user sessions:

public static String CacheOffset = "?Cache=" + ; System.DateTime.Now.Ticks.ToString() ;

If you wanted to update the image during a session then it would simply be a case of populating your image source using a different ‘virtual cache’ value for CacheOffset.

I suspect there may be better ways to achieve the same objective but for now this works for me.

Following a gruelling (OK, not really that gruelling) 2 days in the Labs at Microsoft a couple of weeks ago am happy to say that “Live Tile Browser” has received certification for submission to the Windows 8 store.  (I understand that this is one of the first, if not the very first app in the UK to do so!)

I received some great feedback as a result of my time in the labs, much of which has been put to use in developing improvements to the App itself. 

Live Tile Browser should be available with the next iteration of Windows 8 (release candidate) some time next month!

There are still a couple of surprises held back for the App’s release and a video is needed to do justice to the smooth animation but for now here are a few screenshots of the current build:

The first chart shows downloads for April – with the healthy spike being a result of the coverage received.

The second chart is specific to “Live Tile News” and shows the more dramatic spike in interest as a result of the show.

The vast majority of downloads were, as might be expected, in the UK but as this App supports US and Global news it will be interesting to monitor if there is any knock on effect in these territories going forward.

Ian

NB The review can be viewed on my earlier blog post here

Live Tile News (Ad Supported)

Live Tile News (Premium)

Kate Russell reviews ‘Live Tile News’

If you don’t already have this app why not try one of the following options:

• Free (Ad Supported)
• 99c/79p (no ads)

(All developer proceeds from Ads and Sales go to charity)

“We are reaching out to ask your permission to cross-submit each of your Windows Phone apps into the markets* identified below, which includes more than 25 new markets.  We realize that the process to cross-submit takes time out of your busy schedule, so we are requesting your permission to submit all of your applications on your behalf to save you time and effort.  This will provide an opportunity for your apps to get additional exposure in new markets which may lead to more downloads and more revenue for your app(s).”

PERMISSION TO CROSS SUBMIT YOUR APPLICATION(S) TO NEW MARKETS:

Please respond by Friday April 27^th, 2012 11:59PM PST by replying directly to this email  stating one of the following:

1) “Yes. I authorize cross-submissions.”

a. I authorize Microsoft to cross-submit each of my apps into all markets*.

2) “Yes. I authorize cross-submissions with exceptions.”

a. I authorize Microsoft to cross-submit my apps into all markets* with the following limitations: (please list any apps that you do not want submitted in the new markets and/or any new markets you want to exclude from submission)

3) “No. I will cross-submit to new markets myself through App Hub.”

a. We will not take any action without your reply, and a reply is not required. However, if you respond with this option, we will note your preference and will not send a follow-up email on this topic.

Please respond from the email address associated with your developer account to expedite the process as we will not be able to act on replies from other email addresses.

APPLICATION MARKETS:

* Windows Phone Marketplace now includes Bulgaria, Costa Rica, Croatia, Estonia, Iceland, Latvia, Lithuania, Romania, Slovakia, Slovenia, Turkey, Ukraine, and Venezuela and will announce UAE, Bahrain, Iraq, Saudi Arabia, Qatar, Kazakhstan, Israel, Thailand, and Vietnam.   These add to the previously launched markets of Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Colombia, Czech Republic, Denmark, Finland, France, Germany, Greece, Hong Kong, Hungary, India, Indonesia, Italy, Japan, Malaysia, Mexico, Netherlands, New Zealand, Norway, Peru, Philippines, Poland, Portugal, Russia, Singapore, South Africa, South Korea, Spain, Sweden, Switzerland, Taiwan, United Kingdom, and United States.

ADDITIONAL REMINDERS:

· The terms of the Application Provider Agreement apply to the publication of your Application(s) in any additional markets.

· For paid applications, Microsoft will convert the USD base price you’ve provided into the applicable local currencies [include link to KB article on international price conversions]. 

· By replying to this email, you affirm you are authorized to respond on behalf of the developer account.

· Cross-submission of you application(s) may not occur for all markets; please check your account to confirm the markets in which your application(s) become(s) available.

Sincerely,

The Windows Phone Marketplace Team

Cross submitting existing apps is a win-win for developers and for Microsoft and I would urge anyone to do this themselves through the existing App Hub process.

Disclaimer: I have quite a large number of apps in the marketplace which may be some kind of qualifying criteria? 

Metro style design has a set of five guiding principles to help you make the best choices when designing your app. These principles are the foundation for building great Metro style apps. Consider these principles as you plan your app, and always ensure your design and development choices live up to these principles.

Show pride in craftsmanship

Devote time and energy to small things that are seen often by many of your users, and engineer the experience to be complete and polished at every stage.

• Sweat the details.
• Make using apps safe and reliable.
• Use balance, symmetry, and hierarchy to foster trust and a sense of integrity.
• Align your app layout to the grid, the classic Metro style layout for apps.

Be fast and fluid

Let people interact directly with content, and respond to actions quickly with matching energy. Bring life to the experience by creating a sense of continuity and telling a story through meaningful use of motion.

• Be responsive to user interaction and ready for the next interaction.
• Design for touch and intuitive interaction.
• Delight your users with motion.
• Create a UI that is immersive and compelling.

Be authentically digital

Take full advantage of the digital medium. Remove physical boundaries to create experiences that are more efficient and effortless than reality. Being authentically digital means embracing the fact that apps are pixels on a screen and designing with colours and images that go beyond the limits of the real world.

• Connect to the cloud so that your users can stay connected to each other.
• Be dynamic and alive with communication.
• Use typography beautifully.
• Use bold, vibrant colours.
• Use motion meaningfully.

Do more with less

You can do more with less by reducing your design to its essence, and solving for distractions, not discoverability. Create a clean and purposeful experience by leaving only the most relevant elements on screen so people can be immersed in the content.

• Be great at something instead of mediocre at many things.
• Put content before chrome.
• Be visually focused and direct, letting people get immersed in what they love, and they will explore the rest.
• Inspire confidence in users.

Desktop browsers have quite a lot of chrome (menus, options, status bars, and so on) that is only sometimes useful. Typically, however, users open a browser to see a webpage, not to interact with the browser. Moving commands off the browser chrome and into the app bar or into charms helps users focus on what they care about.

Win as one

Work with other apps, devices, and the system to complete scenarios for people, like picking content from one app and sharing it with another. Take advantage of what people already know, like standard touch gestures and charms, to provide a sense of familiarity, control, and confidence.

• Fit into the UI model.
• Reduce redundancy in your UI.
• Work with other apps to complete scenarios by participating in app contracts.
• Use our tools and templates to promote consistency.

(Reproduced from http://msdn.microsoft.com/en-us/library/windows/apps/Hh781237.aspx)

Update

It occurred to me that it would be useful to have some kind of a ‘Windows 8 feature Check’ for new Apps along the lines of ‘have I considered this new feature for my own App’.  I was about to craft such a blog post when I stumbled on this excellent post from Microsoft:

http://msdn.microsoft.com/en-us/library/windows/apps/hh465424

The latest version, as well as including many more live tiles (on average we are seeing around 15-20 new Live Tiles a week) now includes a useful filtering utility:

As you touch one of the filters and swipe to the tile pages you only see relevant Live tiles matching your filter selection.  In addition a small filter icon appears at the bottom left of the screen to indicate that a filter is in effect (tapping this icon will also take you to the filter screen)

I’m not sure yet about the UI implementation of the filtering page and may well switch it out to utilise the Windows Phone Menu system instead – Please let me know if you have any thoughts on that.

The categories are dynamic such that as new tiles become available, relevant  filter options are picked up automagically.  As you might expects the categories are the same as those in the Windows 8 App and in the Silverlight version of the App at http://liveTiles.co.uk.

Some of the latest Live Tiles

The update is currently undergoing testing and should be available through the marketplace soon.

In the meantime you can download the current (and free) version ‘Live Tile Browser’ HERE.

I’m not going to labour the point but the installation of the Windows 8 Consumer Preview is a lot easier than my earlier post relating to the Dell Duo!  That said, the steps are essentially the same:

• Back up the supplied Windows 7 installation if desired*
• Install Windows 8
• Run Windows Update
• Download Windows 7 drivers from the ASUS Site
• Install the drivers

* I say if desired as unlike the Dell Duo the Asus comes with a Windows 7 restoration disk.

Here are the steps I took in a little more detail:

Installing Windows 8

NB I used a USB Keyboard which I left connected throughout the process in order to make any text entry (WiFi passwords etc) easier, I also copied the Windows 8 key onto the same USB stick I used for the update process so that all I had to do was copy and paste it when requested.

1. Download the Windows 8 image (DOWNLOAD)
2. Mount the downloaded iso file (I used MagicISO)
3. Run the setup program and follow the installation instructions given

NB I chose the 64bit O/S over the 32bit owing to the generous memory available on the device (4GB) and the fact that ASUS supplied the 64bit version of Win7 with the machine, rather than the 32bit  in the first place).

An alternative methodology might be to burn the downloaded image to a DVD Drive then utilize an External DVD Drive instead of using MagicISO.

Running Windows Update

This is essentially the same process as for Windows 7 – from the Win8 menu choose Control Panel and walk through the following screens before finally running Windows update:

NB You can also simply type ‘control’ when in the Metro desktop interface to switch to the Metro control panel, and from there select ‘windows update’

Downloading Windows 7 drivers from ASUS

The consumer build of Windows 8 does a pretty good job of managing the drivers and software from the previous Windows 7 installation.  However it is worth keeping an eye on the 64bit downloads from ASUS in case there is a firmware upgrade or some updated device drivers that don’t make it through the default Windows update process.  The download page is located here:  ASUS support page

Performance Rating:

(Noticeably superior to the Duo as you might expect.)

Notes

Now that this device appears to be available at reasonable rates on eBay I have to say that it is probably the best choice in terms of value and performance for a slate type device at the time of writing (March 2012).  If you can afford it the Samsung series 7 Slate is probably top  dog, with the EP21 a close second and a definite winner in price terms.  The dell Duo remains a great choice for testing the waters and is certainly more than capable of running the majority of Metro apps currently available.

ASUS App Compatibility

DNLA

I was particularly pleased to note that the ASUS DLNA server (Mediacontroller.exe) still continued to work after the upgrade – this is a useful utility to have on any slate device that allows pictures and videos to play to any DLNA equipped TV.

Art Rage

Art Rage is bundled with the Windows 7 install of the EP21 and is a great way to show off the tablet oriented features of the device.  It loads fine but I found the functionality to be questionable under Windows 8.

(All the other apps supplied by ASUS appeared to work OK under Windows 8).

Tips:

ASUS Applications

If you intend to use any of the Asus applications that came with the Windows 7 software it is a good idea to pin them to the new Metro desktop.  This can be achieved by holding down on the relevant exe file until the in place menu appears that has the option to pin. Most of these apps can be found under c:\program files\Asus\

Bluetooth Keyboard

If you find that Blutooth isn’t working properly try downloading the ‘Wireless Lan’ Drivers from the Asus Site:

Extract them and run setup – it will fail saying that this is the wrong version of windows.

NB UNISTALL any previous version if you see this message:

Go on to the install :

A few of seconds you should get a windows popup asking if it worked ok – click no- re-run in compatibility mode.
The install will now run OK – I deselected the WLAN driver (as Wireless is working fine anyway) and let it install the Bluetooth stuff:

The Bluetooth icon appeared on the system tray – open the settings from here once the installer has finished and click the ‘allow devices to see this PC’ option (not sure if this is absolutely necessary ).
Then held down the Bluetooth button on the keyboard , went into the ‘add device’ option in the control panel and the devices showed up, connected first time and just worked.

(With thanks to Mark Blackburn)

http://social.msdn.microsoft.com/Forums/en-US/windowsdeveloperpreviewgeneral/thread/747de215-f319-4aea-8762-2480573456e2

A quick interim post to show progress on porting this app to Windows 8. Still much to do but have made good progress in a couple of days.  Plan on adding filters for Live Tile types which will re-arrange the screen accordingly.  UI is very responsive so am pleased thus far.

I have added filters using the App menu bar which makes things a bit more manageable.

I have also added a ‘shrink’ option that takes tiles down to just a basic text description.  I am looking to have this follow the functionality of the ‘semantic zoom’ control but my first attempt to do this resulted in a spectacular fail!

NB This App forms the basis for my continued support of “App Aid” and will be followed by a WinRT / Metro version of “Live Tile News”.

Ian.

UPDATE

Stay tuned for an update on this post when I highlight how applying some of the common Windows 8 metro design guidelines has an impact on the next iteration of this app!

"Oil Painting"
"Watercolours"
"Pencil Drawing"
"Charcoal Drawing"
"Origami"
"Sand Sculptures"
"Chalk Drawings"
"Screen Printing"

Well, now is your chance!

Watch, Rewind, Replay & Pause a constantly refreshed catalogue of some of the most talented artists explaining in detail how they do what they do.

Pin any of the 8 artist types to your phones home screen – as a new clip is published you will see it appear here, clicking through will take you to the clip section within the app!

★★★★★ "What a great app!"

★★★★★ "Just watching these people is art in itself!"

★★★★★ "Thank You!"

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Try the free demo today!

http://windowsphone.com/s?appid=f0e90985-dc7a-4ae8-a057-e45db2c92ea3