Enjoy live cameras from across the world on your smartphone

This app has won the "2019 December's MIT APP INVENTOR OF THE MONTH" award. 
http://appinventor.mit.edu/explore/app-month-winners-2019

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The source code (blocks) is published below:
ai2.appinventor.mit.edu/?galleryId=6239670284976128

Revision: Added a function to automatically acquire images periodically (see Fig. 4).
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Many live cameras are installed in cities, mountains, rivers, etc. around the world. They are useful for knowing the current situation in a nostalgic place or where an acquaintance lives. Of course, you can simply enjoy the beautiful scenery. It takes a little time to find a suitable one among those live cameras. There are not so many live cameras that are of interest to each person, at most about ten. If that's the case, don't you think it's convenient to register them in advance on your smartphone so that you can see them right away! At that time, it would be nice to be able to display the previous camera image together with the current camera image. It's often useful to know that something has changed in a few hours.

First, find out several suitable live cameras. They can be video images or still images. Also, the update interval varies from several minutes to one hour. Here, select still images with an update interval of several minutes. MIT App Inventor is very suitable for the smartphone app to be created this time.

Prepare a text file with the location name and image URL as input data. From such a text file, create a simple database with TinyDB, and through that, let the Web component get images. The acquired image is displayed with the Image component together with the current time. The saved previous image is also displayed at the same time. In addition, we added a function to automatically delete images that were not saved so as not to occupy a large amount of storage.

This is a simple app, but you can use it to see the image of the desired live camera as soon as you think of it. You can save your favorite images by pressing the button. It's also a good idea to email screenshots of current and past images to someone else.

Fig.1 shows the case where Mt. Fuji (FujiYoshida) is selected from 10 registered live cameras ([1]-[10]). It is interesting to compare this morning's image with yesterday's image.

Another examples are shown in Fig.2. Images from two live cameras (Liverpool Airport and Liverpool Waterfront) installed in Liverpool. Time is shown in Japan time. It ’s also fun to compare day and night images.

Some live cameras have a telephoto function and a variable direction shooting function. These features are switched automatically and cannot be controlled by the user, but if you are lucky you can get even better images. For example, Fig. 3 shows Mt. Fuji taken with the telephoto function and the night view of Sapporo taken from different directions.

Now we have added a function to periodically acquire images from the current Live camera. As shown in Fig.4, you can specify the shooting interval and press the button to automatically update the screen. And automatic shooting stops by Long-Click on the button.

please note
If Error_908 is displayed when running this app, please allow access to External_Storage in your Android settings. Please allow it again (twice) if necessary.

References

(The live camera URL is not shown below because some live cameras do not allow direct links to images, except for personal use.)
[1] Neuburg an der Donau

[2] Mt. Fuji Subashiri

[3] Sapporo Oh-dori park

[4] Liverpool AirPort

[5] Tokyo Haneda AirPort

[6] Kushiro Japan

[7] London Big Ben

[8] Mt. Fuji Fujiyoshida

[9] Liverpool Waterfront

[10] Chikuma river Naganuma