Follow SpaceX flights with SpaceXLaunches for Android
SpaceXLaunches is an Android app for keeping track of SpaceX space launches:

https://play.google.com/store/apps/details?id=com.danielscholte.spacexlaunches

It’s a simple but effective app that packs a lot of useful information in an easy to use tool.

Price
Free

Features
The app provides data about upcoming SpaceX launches as well as launch notifications and statistics on past flights. It also lets you track how vehicles and components were used such as booster cores and Dragon capsules. Links to external resources like launch webcasts are also available.

Usage
The home screen of SpaceXLaunches features a slideshow of SpaceX vehicles and launches with a card at the bottom listing the next launch. Tap the card to expand it and get additional information and links to external resources like the press kit, the webcast, and relevant Reddit threads.

The main menu has options for opening screens with upcoming and past launches. In these screens tap an entry for more details.

Section Vehicles of the main menu has options for gettings lists of SpaceX launchers and capsules. You can also get lists of rocket cores and capsules used in past missions (Track Cores and Track Capsules), which is especially useful for tracking which component was used in which mission(s).

Finally, the menu has a couple of additional options for getting a list of launch pads and changing the app’s settings. The most useful settings are those for switching to a light or dark theme and controlling launch notifications.

Tips
The Track Cores and Track Capsules options of the main menu feature icons for showing at a glance which components are active, retired, destroyed, or expended.

When you open a details card be sure to scroll down for more content such as links to additional resources. Tap the device’s Back button or swipe down to dismiss the card.

Screenshot
The past launches screen of SpaceXLaunches on my Pixel 2 XL phone.

Using Stellarium Mobile for Android on a Chromebook
I recently got a new Chromebook, a Lenovo N23 Yoga with support for Android apps:

My new Chromebook: first impressions
https://plus.google.com/+PaoloAmoroso/posts/BXfRfF4mZda

And, of course, I’m using it also with astronomy and space apps for Android, starting with the Stellarium Mobile Sky Map planetarium app:

https://play.google.com/store/apps/details?id=com.noctuasoftware.stellarium

It works well on the Chromebook, both in a window and at full screen. In tablet mode the Chrome OS dock appears as expected. Performance is good too, with the view draggable smoothly enough at full screen.

You can entirely control the app with the touchpad, a mouse, or the device’s touch screen. With the mouse and touchpad you have to use the + and - zoom icons as, of course, pinch to zoom requires the touch screen.

Stellarium Mobile doesn’t provide much support for the keyboard but a notable useful keystroke for Android apps on Chrome OS is the device’s Back button for going back to a previous screen, such as for dismissing a dialog.

Screenshot
Stellarium Mobile for Android on my Lenovo N23 Yoga Chromebook.

View Mars rover images with The Red Planet Mars for Android
The Red Planet Mars is an Android app for viewing images of the surface of Mars by NASA’s rovers:

https://play.google.com/store/apps/details?id=com.bsunk.theredplanetmars

Simplicity is the key point of this app, which features a Material Design user interface. However, it would have been useful to have a few more options such as filtering by camera type.

Price
Free

Features
The Red Planet Mars lets you browse the database of the images taken on the surface of Mars by NASA’s rovers Spirit, Opportunity, and Curiosity. You can change date and share or favorite specific images.

Usage
The main screen features a tabbed interface with a stream of thumbnails of the selected rover in reverse chronological order. Tap the rover name in the bar at the bottom to switch to the corresponding image stream or the hearth icon to open the favorites screen. Swipe down to refresh.

Tap ain image to view it, pinch to zoom. You can add an image to your favorites by tapping the hearth icon. There’s also a share icon for sharing the image.

To view the images taken at a different date tap the calendar icon at the top of the screen.

Tips
The image stream of rovers such as Spirit and Opportunity are permanently or temporarily blank as the rovers haven’t been sending images for a while. Be sure to switch to a date in the past to see their images.

Screenshot
The main screen of The Red Planet Mars on my Pixel 2 XL phone.

Using space apps for Android on Chrome OS
I finally got a Chromebook that can run Android apps, a Lenovo N23 Yoga:

My new Chromebook: first impressions
https://plus.google.com/+PaoloAmoroso/posts/BXfRfF4mZda

None of my other Chrome OS devices, an ASUS Chromebox and an Acer C720 Chromebook, support Android apps and I was missing the Android action on Chrome OS. Now I can test and experiment with Android apps on the desktop, including astronomy and space apps.

Screenshot
The screenshot shows for example Stellarium Mobile for Android running full screen on my N23. I’m going to post more here about how Android apps for space and astronomy run and work on Chrome OS.

See also
I posted about Stellarium Mobile here:

How to exit full-screen mode in Stellarium for Android
https://plus.google.com/+PaoloAmoroso/posts/LqMUPFD9KMd

Monitor the transient sky with Gaia Alerts for Android
Gaia Alerts is an app for getting reports of transient celestial objects observed by ESA’s Gaia orbiting astronomical observatory:

https://play.google.com/store/apps/details?id=uk.ac.cam.ast.gaialerts

Gaia is a European astrophysics space mission for mapping a huge number of stars in our Milky Way galaxy. As a byproduct of its observations the science team issues alerts about transient objects.

Price
Free

Features
Gaia Alerts shows on a map of the sky the transient objects observed by Gaia, i.e. objects that change, appear, or disappear. For each it provides an image and basic data such as the classification, coordinates, and brightness.

Usage
The main screen features a map of the sky with transient objects shown as red dots. Pinch to zoom, tap and drag to scroll or pan around. Tapping a red dot brings up a card with data on the selected transient object.

Tapping the 3-lines icon opens a menu with a list of alerts, i.e. reports of transient objects. Tap an alert to open it and show an image with basic data. The menu accessed by tapping the MENU icon has options for learning about Gaia, how to interpret the data the app provides, and other information.

Tips
When opening it for a new session the app takes a lot to download and update its database even on high end devices with good network connections, so be patient.

The map of the sky is small and packed with touch targets, therefore it’s easy to miss the one you’re interested in or hit a different one. Before tapping a red dot be sure to zoom the map a bit to make dots larger and easier to hit.

Screenshot
The image and data of a transient object, a Young Stellar Object (YSO), shown by Gaia Alerts on my Pixel 2 XL phone.

View the virtual Moon close in the sky with Giant Moon AR for Android
Giant Moon AR is an Android app for showing the Moon in an Augmented Reality environment as if it was much closer to the Earth:

https://play.google.com/store/apps/details?id=com.arrowsd.giantmoon

It doesn’t do much but it’s a cool demo. The app requires ARcore which is currently available only on a handful of Android devices, so it may not work on yours.

Price
Paid

Features
Giant Moon AR shows the virtual Moon as it would appear if its surface was around 400 km away from the Earth’s, i.e. at the same orbital altitude of the International Space Station. This imaginary Moon can be seen in the AR environment visible through your phone camera. The app also lets you take screenshots.

Usage
Once you start the app point the phone’s camera to the horizon and keep it still until the Moon appears. Then move the device to follow the Moon quickly rising in the sky.

Tap the camera icon to take a screenshot. The cloud icon lets you toggle between showing the virtual Moon in front or behind the clouds of the real sky.

Tips
For best visual results don’t use the app in a cloudy day or at night. And for better realism be sure to set the app to display the Moon behind the clouds.

The screenshot button opens a modal dialog, an inconvenience when you need to take several screenshots in a row. In this case it’s better to use your device’s built-in screenshot capture gesture, usually simultaneously pressing the Power and Volume Down buttons.

Screenshot
The view through the camera of my Pixel 2 XL phone in Giant Moon AR.

View the planets’ positions at a glance with Skywheel for Android
Skywheel is an Android app for viewing the positions in the sky of the planets and other Solar System objects:

https://play.google.com/store/apps/details?id=com.xeronaut.skywheel

I love the simplicity and effectiveness of Skywheel, which features a nice Material Design user interface. It shows the planet’s positions at a glance like a sort of infographic.

Price
Free

Features
The app shows the celestial sphere with the positions of the planets. You can get info cards with the coordinates, upcoming celestial events, and other basic data about the planets and other Solar System objects.

Usage
Skywheel’s main screen displays a simplified map of the sky at the current time and location, with the positions of the planets in the sky above or below the horizon. Tap and drag the map to rotate the it.

Tap the list icon at the bottom right to open a screen with cards showing the current position data for the Solar System objects. Tapping an object in the map and then DETAILS opens the corresponding card.

The calendar icon gives access to a screen with a list of upcoming celestial phenomena such as rising and setting times, lunar phases, and more.

The main menu, which you can open by tapping the hamburger icon, has options for going back to the sky map, opening the info cards screen, setting the observing location, changing the date and time, opening the events screen, and changing the app’s settings.

Tips
If you are in Europe you may prefer to change the time format to 24 hours under Settings > 24 Hour Clock.

Screenshot
The main screen of Skywheel on my Pixel 2 XL phone.

Explore the planets in Augmented Reality with Solar System AR for Android
Solar System AR (ARCore) is an Android app for viewing a model of the Solar System in an Augmented Reality environment:

https://play.google.com/store/apps/details?id=com.guidapasquale.solarsystemar

The app runs only on Android devices with version Oreo 8 or later and support for Google’s ARcore library, which right now are just a handful of models.

The app is a cool demo with a lot of potential. But it’s currently very limited as the 3D model is not to scale neither for planet distances nor sizes. I’m not sure whether the positions of the planets along the orbits are accurate. And you can’t resize the model but the developer is planning to add this feature.

Price
Free ad-supported, optional in-app purchase for removing the ads

Features
Solar System AR (ARCore) lets you only view a model of the Solar System overlaid on the Augmented Reality environment seen through the device’s camera.

Usage
After a welcome screen, the main screen prompts you to tap the camera’s viewfinder to place the model in the environment. Move around to explore the model.

The Info button toggles the planet labels, the Sun/Moon icon turns off the camera feed and shows only the planets. Tap the menu icon to get a sharing and info menu. The Reset button lets you place the model again.

Tips
When setting up the model be sure to frame through the camera an area with a large open surface.

Screenshot
The Solar System model in front of the Planetarium of Milan, Italy, seen through Solar System AR on my Pixel 2 XL phone.