Android Development, Documentation, Products, Software, Uncategorized

How to Place Your App Inventor Apps in the Google Play Store

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An all new tutorial on this subject is available here as of May 2016! There is still some great information below – read both!

Apps you create in App Inventor may be added to the Google Play Store.

The process is not difficult but there are many steps to the process and you will need to create some graphic images to illustrate and promote your app in the store.

Summary of the Steps

  • Set your app’s VersionCode and VersionName.
  • Apply for a Google Developer account (one time fee of US $25 after which you can upload an unlimited number of apps, forever).
  • Create at least two and up to 8 screenshots of your app for display in the store’s app listing.
  • Create a “feature graphic” and a high resolution icon for use in the store listing.
  • Use the App Inventor provided keystore file, or use a keystore file you have created elsewhere or previously.
  • Build and export your app as a .apk file to your computer.
  • Create a title for your app in the store
  • Write a description for your app to appear in the store
  • Decide on free versus paid (paid requires a “merchant account” to be set up).
  • Upload your apk file, keystore file, image files and title and description, and provide some additional information (such as product category, pricing, and target audience).

Continue reading How to Place Your App Inventor Apps in the Google Play Store →

App Inventor News, STEM Education, Uncategorized

App Inventor course available in Spanish

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Estructurado en 8 módulos y con más de 146 clases este curso es ideal para aquellas personas que, sin tener idea de programación, quieren tener un curso completo de App Inventor paso a paso y basado en la metodología de aprender haciendo.

Curso de Desarrollo de aplicaciones móviles Android con App Inventor

The 22 hour online course is offered through the udemy.com

(I did not make clear – sorry – this course is from Professor José Luis Núñez and he is offering it through udemy.com. I am not involved in this at all – just sharing the link – Ed)

Documentation, Uncategorized

App Inventor 2 Advanced Concepts and AI2 Databases and Files now available at Google

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After a processing delay, both e-books are now also available at Google Play Books.

App Inventor 2 – Advanced Concepts (Volume 2)

Download sample chapter: App_Inventor_2_Advanced_Concepts_Chap1.pdf

Where to Buy

App  Inventor 2 Databases and Files (Volume 3)

Download sample chapter: App_Inventor_2_Databases_Chap1.pdf

Where to Buy

Documentation, General, Uncategorized

New – e-book corrections page with updates, fixes

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I have set up a page to collect any corrections to my e-books. If you find issues in the books, post a comment here on the blog (http://appinventor.pevest.com) or on my App Inventor 2 Facebook page.

Todd F. found an odd set of sample blocks code images in Chapter 3 of App Inventor 2 Databases and Files (1st edition Revision “A”-see page 2 for the revision level).

I inadvertently inserted two incorrect blocks code samples at the very end of Chapter 3. The correct images are show here.

Any future bugs in the text will be noted on the E-book Corrections page and rolled in to the next e-book update. If you spot any problems, please leave us a comment on any page here on the blog or on our Facebook page – I get notified each time a comment is posted.

Update on Google Books Version

The Google Books e-book version of Volume 2 and Volume 3 has been stuck in their “processing” system for about 5 weeks. I contacted their support staff today and there is an unknown problem with the epub format file (a file used to describe an e-book) for these titles. I am looking into that and hope that it can be fixed soon.

App Inventor News, Components, Documentation, Uncategorized

App Inventor introduces copy and paste of code blocks!

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App Inventor has introduced “copy and paste” of code blocks. Now you can copy blocks of code within a current screen, or from one screen to another screen, or even between projects. This is great news!

Look for the “backpack” icon at upper right of the blocks Viewer screen:

AI_Copy1

Select a block or blocks with the mouse pointer, and then click and drag the selected blocks into the backpack. A copy of the blocks are placed into the backpack and your original blocks also remain in the editing window.

Click on the backpack icon and it displays the code blocks currently stored in the backpack:

AI_Copy2

Click on the code block in the backpack (at right) and drag it into the Blocks Viewer. That is all you need to do to copy blocks.

Use this feature to copy blocks within your current screen, or to copy blocks from one screen to another screen, or to copy blocks from one app to another app.

You can put several blocks into the backpack, and then select only the ones you wish to copy over to another blocks Viewer.

How do you empty the backpack? It seems the only way to empty the backpack of saved items is to close the editing windows, go back to the MIT App Inventor home page (http://appinventor.mit.edu/) and select the Create apps! button to re-enter the designer and blocks editor.

Regardless, this is a GREAT NEW FEATURE! Thanks MIT App Inventor team!

General, Programming Method, Uncategorized

Implementing an “Array” in App Inventor

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What is an “Array”?

An array is a variable data type that stores a collection of values referenced by an index number.

For example, suppose we wished to store the names of the 12 months of the year: January, February, March, … , November, December so we can convert a month number to a text name. Month 1 converts to “January”, Month 2 converts to “February” and Month 12 converts to “December”.

An easy way to do this conversion is to set up an array that, in concept, looks something like this:

Month[1] = “January”
Month[2] = “February”
Month[3] = “March”
Month[4] = “April”
Month[5] = “May”
Month[6] = “June”
Month[7] = “July”
Month[8] = “August”
Month[9] = “September”
Month[10] = “October”
Month[11] = “November”
Month[12] = “December”

Month is the name of this variable – but unlike other variables, this one stores 12 separate values. Each value is referenced by using an index – if the index value is 2, then Month[index] refers to “February”.

If we have a date, such as (US-style) – 2/14/15, meaning February 15, 2015, we can convert the month number of 2, into the text month name by referencing Month[2].

If you have studied algebra math or beyond, you have encountered array variables such as X1, X2, X3, … Xn where the value Xi is read as “X subscript i”. This is the same concept as an array of values. If you have not studied algebra, this notation may be new to you. 

Most programming languages support an array variable type but App Inventor does not support arrays. Yet arrays are a convenient way of storing and working with some types of data. To support an array-like variable in App Inventor, we can use a list and map the array subscript to an index position in the list.  By hiding this within a couple of procedures, we can simulate the array variable type.

Sample User Interface

I created a simple app to demonstrate the use and implementation of the array. You can download this app from the MIT App Inventor Gallery here.

Continue reading Implementing an “Array” in App Inventor →

Documentation, General, Uncategorized

Tip on inserting images into Microsoft Word

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Off topic a bit but this may be helpful to others inserting images into Microsoft Word documents or trying to create better images in e-books.

E-Book Images

The past few days I have been looking at ways to improve the image quality in e-books. Images are not handled well by e-book development software and some of the problems are due to undocumented “features” and software defects.

Three common file formats for images are JPG, GIF and PNG. JPG images are good for photos but not great for drawings (like App Inventor block code). However, Amazon secretly decides on its own whether or not one’s JPG images are sufficiently compressed and makes its own secret decision to recompress the original JPG even more, losing resolution in the e-book.

Images that start as PNG files are converted to JPG files by the software that creates the e-book formatted files.

GIF files go through the process “as is” and remain as unchanged GIF files. GIF files are best for drawings (rather than pictures) with lots of solid colors. Therefore it is best to use GIF files for illustrations such as App Inventor “blocks code”.

The basic rule for e-book authors is to use JPG images for photos and GIF files for drawings and illustrations (non-photo images).

Microsoft Word Turns Inserted Images into Blurry Images!

Today I discovered Microsoft Word converts clean GIF images into blurry images when GIF files are added to a document.

I was working with a document that had older images, captured and inserted differently some time ago. Those images looked nice and sharp. But when I imported new GIF screen captures, the new images looked soft and fuzzy. Word is converting (and recompressing) the imported GIF files and reducing their image quality. There is no way to turn this “feature” off in Word! This “feature” creates images that are unsuitable for e-books or printed book use.

This is a “known defect” (“feature”) introduced by Microsoft Office Word in 2010. I discovered this on Mac OS X Office 2011. The work around is save your Word document in the older 1997-2004 .doc file format. Now, when you insert images into the file, they appear correctly.

This is documented in a Microsoft forum here. Related issue in MS Powerpoint.

Afterword: I also tried OpenOffice, which I like, but ran into other problems there such that OO was not a solution either.

Android Development, Components, Programming Method, Uncategorized

How to use the “2 Button” Notifier dialog box

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A reader asked, “When using the 2 button Notifier dialog, how do we know which button was pressed?”

The 2 button Notifier dialog alert box displays 3 buttons(!) – the first two have values you specify, such as “Ok” and “Done”, as shown here, and the third is an optional generic “Cancel” button:

Screenshot_2015-09-11-15-07-15

The Notifier component block is a procedure call that has no return value – so how can you determine which button was selected?

The answer is that the selected button is returned to a separate event handler.

Continue reading How to use the “2 Button” Notifier dialog box →

Products, Uncategorized

Poll: Do you prefer printed books (cost more) or ebooks (cost less)?

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Some of my readers have asked about printed copies of my App Inventor e-books.

There are services available that can print high quality, full color (with more detailed images) “on demand” which means a copy of the book is printed and manufactured at the time of purchase.

Printing adds cost. Depending on the size (height and width) and length of the printed book, prices might fall in the range of US$10 to $20.

Are you interested in printed books or are e-books okay with you? Here’s a quick poll on the subject – this poll also appears in the lower right side bar of this web page.

Thank you for your help!

[poll id=”3″]

Components, Documentation, Programming Method, STEM Education, Uncategorized

Tip: Using component colors to find components in the Blocks Editor

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Finding a specific programming block with in the AI2 Blocks editor can be hard for new AI programmers.

You found a great code example online and want to recreate it by entering the blocks in to your program – but you cannot find that red block in the middle of the code sample? Where is it? !!!

You start poking around the drop down lists, scanning up and down the pop up menus, missing it the first time(!) and then going through all the blocks again until you finally locate that darned block! Frustrating!

Continue reading Tip: Using component colors to find components in the Blocks Editor →

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