Why I built SolvoKu

  • Some projects are made not for the expected result, but for the journey to attain it.

  • SolvoKu was built with this in mind.

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Time for some numbers

Now that SoHO Viewer has been downloaded more than 50,000 times (51,1K according to itunesconnect reportings), it is time to give some numbers about it.

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Loyd's Puzzle 2.4.0, Rotary Puzzle 1.4.0, Astro Kit 1.1

Summary of last updates:

Astro Kit - 1.1.0

Waiting for review:
Rotary Puzzle 2 - 1.1.0
Rotary Puzzle - 1.4.0
Loyd's Puzzle - 2.4.0

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Rotary Puzzle 2 - V1.1.0 waiting for review

Rotary Puzzle 2 version 1.1.0 will add Spanish and Portuguese localizations. Memory management is improved.

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Astro Kit 1.1 waiting for review

Astro Kit version 1.1 will add Spanish and Portuguese localizations.

Read more…

SpiderChart 2.0.1

SpiderChart 2.0.1 is now available on the AppStore, it fixes a bug present in the previous version causing a crash for iPad users.

SpiderChart 2.0 issue

A bug is present in the last update of SpiderChart causing a crash when launched on iPad.

A fixed version is already waiting for Apple's Approval.

I apology for the inconveniences caused by this situation.

SpiderChart 2.0 waiting for review

The longly awaited spiderchart version 2.0 has finally being submitted to Apple, it is currently waiting for review.Read more…


Today the total number of downloads, including updates, for my iOS applications has exceeded 250,000

SoHO Viewer 2.2.2

SoHO Viewer version 2.2.2 is waiting for review.

It correct bugs that appeared in previous update.

SoHO Viewer: what's really behind the application.

When the SOHO Viewer application refresh its content, the process is a bit more complex than just downloading images from a website. Well, first versions used to do so but since version 2.0 of SoHO Viewer another mechanism is used.
Read more…

SoHO Viewer 2.1 issues

Since version 2.1 SoHO Viewer has notifications push, this new functionality has caused an overload on the gateway which has resulted on severe application freeze on launch. The gateway has since been re-designed to support a greater load.

A new update of SoHO Viewer (2.1.1) is currently waiting for review, this update will help to further more reduce the stress on the gateway and prevent the application from freezing if such an overload should occurs again.

The Taquin Game

If all goes well, you will soon be able to use the first game software I ever wrote.
Taquin is a puzzle game, where YOU choose the picture you want to use, and the number of pieces.

Two hints mode will be availables:

  • shortly display the solved puzzle,

  • switch between picture pieces and number ones

Localization: English French
An automatic solver might be added in a next version.

Loyd's puzzle/Le jeu du taquin: available in your favorite AppStore

After days of wait, the "Your application is Ready for Sale" mail finally arrived.
You can now buy it for the cheap price of 0.99$ (= 0.79&euroWinking. Evolutions are already scheduled.
For more informations, please visit
Loyd's puzzle

SoHO Viewer: the sun in pictures This represents my second iPhone application validated by Apple ! More info here

As you may have already noticed, another page made its apparition : "SoHO Viewer".
This represents my second iPhone application validated by Apple !
More info

SoHO Viewer and the NASA

As some of you may have already noticed, there are some words about SoHO Viewer on the NASA's website
Check out the SOHO Viewer iPhone Application. Freeware. Download (
Download and Information). Credit: .Jerome Diaz.
I must admit that it's very gratifying to see that they talk about my work, even if only a few words.

Comme certains s'en sont peut être aperçu, il y a une référence à SoHO Viewer sur le site de la NASA.
Traduit de l'anglais : Allez voir l'application iPhone SOHO Viewer iPhone Application. Freeware. Téléchargement (
Download and Information). Crédit: .Jérôme Diaz.
Je dois admettre trouver gratifiant de voir une référence à mon travail, même si c'est uniquement sur quelques lignes.

SoHO Viewer 1.5 submitted (approved)

I have just submitted an updated version of SoHO Viewer for review.
What is new in this version?
Improved downloading system with better state indicator.Images are now refreshed on screen as soon as the new picture is retrieved. For improving quality for iPhone 4 and iPad users, the images downloaded are now 1024*1024 instead of 512*512. Improved memory management and performance.

SoHO Viewer 1.5 has been approved.

Ultra universal apps?

On Wednesday it was announced the future launch of the Mac App Store: a place to buy and download applications for your Mac, similarly to the AppStore for iPhone/iTouch/iPad.

This come from the will of making the Mac benefits of the experience acquired with the iPhone and the iPad.

The question that comes now to mind is: Will we now be able to build applications for being compatible with both iOS and Mac OS X? Or at least to build the two versions from a unique xCode project.

SohoViewer 1.6 (update)

An updated version of SoHO Viewer has been submitted to the AppStore and is currently waiting for review.

It's add the long awaited description of the instruments.

Next version will include French localization.

Update: This upgraded version has been approved and should been available in a few hours.

The reference-counted memory management system

Cocoa use a counter, the retainCount to know when an object must be deallocated.

When an object is initialized, its retainCount value is set to one, meaning "I am used at one place".

During it's life, this object may encounter several call to retain or release.

When retain is called, the retainCount value is incremented, meaning "I am used at one more place". Inversely, when release is called, the retainCount value is decremented. When the counter value reaches zero, the object is deallocated.

The autorelease method is a variant to the simple release one. When an object receive this message, it adds itself to the nearest autoreleasepool. When this pool is released or train, all objects that were put in it receive a release message.

You can create your own autoreleasepool, sometimes you must do it. There exist at least one pool in your program, located in the event loop.


As I am writing from my phone, today's article will be short.

When creating your cocoa's application, you will often be asked to set a delegate object. This is not specific to objective-c development.

I will take a simple example : a table. There exists two ways two create cells in a table. The first one is active, we tell the table to add a cell, and we do so for each cell. The second one is passive. When the table want to be draw or updated, he ask our code what it should do.

How many rows should I have? What cell should I display there? What should I do when my cell is selected?

That is delegation. The answers are given by an instance of a class implementing an interface. This object is the delegate.

As a matter of fact, in iOS development, a UITableView use a double delegation. The delegate defines the behavior while the datasource defines the content.

SoHO Viewer quoted as one of the "10 free iPhone apps for spectacular stargazing"

The article
By Michael Cooney, Network World November 22, 2010 07:05 AM ET

SohoViewer 1.8 (available on iTunes)

I have just submitted an updated version of SoHO Viewer to the App Store. It is now waiting for review!

MDI images are now replaced by images from the HMI instrument of the Solar Dynamics Observatory.

Pasted Graphic 1


This update is now available as a free download on the iTunes App Store.