Scarce resources 1 - Memory

There are three resources - internal memory, battery-life and cash - which, to varying extents, most smartphone users try to conserve. I am pretty stingy about all three.

When choosing and using mobile apps, there is almost always a trade-off between utility - the additional functionality, time-saving, or simple pleasure that I expect an app to bring me - and the holy trinity of memory, battery and hard-earned cash.

My HTC Desire is now nearly two years old. It's a great smartphone, but it has only 1GB of internal memory, divided more or less evenly between ROM (app storage) and RAM (current processes). That might sound like a lot of memory, but a significant slice of both ROM and RAM is taken up by the Android operating system itself, and by the various components of the HTC Sense overlay. Even when these are not using RAM memory they take up valuable ROM space, since they cannot be uninstalled. The amount of memory actually available for apps installed from the Android Market or elsewhere is therefore a real constraint. I don't monitor the phone's memory usage closely, but I do know that when the Available space in Internal phone storage falls below 20MB (below, left) then loading or switching between apps begins to slow down. Around the same time, I may start to receive 'Low on space' warnings in the notification bar.

Getting a bit low on available memory (left). If you really must, you can 'Force stop' an app (right), but it's better not to.

In fact, one of the Android operating system's great strengths is its efficient management of device memory. You'll find numerous 'task killer' apps in the Android Market which claim to improve speed and battery life by enabling you to close down apps when you are no longer using them. Don't be taken in. First, leaving Android itself to close apps when the memory they are using is needed by another process produces better results. Second, if you ever do need to shut down (or 'Force close') a rogue app, there's a perfectly good way to do this built right into the operating system. From the homescreen menu, choose Settings / Applications, then Manage applications, then choose the target application and tap on Force stop, as in the screenshot on the right, above. (These instructions are valid for Android 2.2, Froyo.) I have almost never had to do this. For anyone used to Windows computing, Android has a near-miraculous ability to recover gracefully from traumas.

So far, I have only talked about 'internal' storage space. The limited amount of this type of memory available on my HTC Desire makes me very careful about the apps I choose to install. Every app on the phone really has to justify the precious space it takes up. And if I am trying to decide between two apps offering similar functions, then I always tend to favour the one with the smaller installed size.

However, my phone also has plenty of 'external' storage space, with a 16GB microSD memory card fitted. This is where I store the music, photos and documents that I want to be accessible even when I don't have an internet connection. Apps use the SD card to store their data. But it is also possible to move large chunks of most apps to the SD card. This reduces their footprint in internal memory, making space for additional apps. Later versions of Android allow you to move apps to the SD card by default when you install them. But if, like me, you are still on Android 2.2 (Froyo) it is well worth going through all your applications and moving those that allow it to the SD card, if have not already done so. From the homescreen menu, choose Settings / Applications, then Manage applications, then choose the target application and tap on Move to SD card, if available. (If the app does not allow it, the button will be greyed out.)

One word of warning before you starting moving apps to the SD card. Homescreen widgets cannot run from the SD card. For this reason, most apps with widgets do not enable the 'Move to SD card' option, but some do. If you move such an app to the SD card you'll almost certainly find that its widget no longer works. If this happens, move the app back to the phone. You will probably then need to reboot the device by powering it down and powering it up again to get the widget to work.

My final memory management tip is to clear out your apps' caches from time to time. Most apps store data of various kinds, and this should not normally be cleared, as it probably includes all your settings. However, many apps also create temporary caches which can grow quite large over time. (The different buttons for clearing data and clearing the cache can be clearly seen on the right-hand screenshot, above.) If you encounter memory shortages, go into Settings / Applications from the homescreen menu, select Manage applications, and press the menu button to sort your apps by size. Go through the ten largest apps one at a time and clear their caches. Browsers in particular rapidly build up large caches. My preferred mobile browser, Dolphin HD, offers options to clear these caches from within its own settings menu - clearing the HTML5 cache may reclaim one or two precious megabytes of space.

To summarise, I recommend three simple strategies for conserving memory on your Android smartphone:

1. Be highly selective in your choice of apps. Avoid duplication and choose small apps where possible.
2. Move as many apps as you can to the SD card.
3. Periodically clear the caches of your most memory-intensive apps.

Next post: Text entry

No place like homescreen

An Android phone is a real hand-held computer. My old Nokia feature phone offered basic calendar, task list and contact management tools. By contrast, I use my HTC Desire to read newsfeeds and books, listen to music and podcasts, write and manage emails, navigate to new places, and a lot more. 

When I have a WiFi connection, I have access to the entire web via a mobile browser - the equivalent of Chrome, Firefox or (if you really must) Internet Explorer. But for most tasks I use applications, or 'apps'. Many of these also draw data from the web and store it on the phone's SD card, so that they can continue to work even when there is no connection. In this post I'll give you a quick tour of the homescreen from which I access these apps.

HTC's proprietary Sense user interface for Android offers a seven-panel homescreen. There's a central 'home homescreen', three panels to its left, and three more to its right. It is easy to arrange application icons and widgets in any way that pleases you. Swiping between panels with a finger or thumb feels entirely natural. To launch an app you tap its icon. Some widgets display continuously updated information such as current weather, track now playing, or latest tweets. Others give direct access to the key features of a specific app. Tapping on a widget usually opens the app itself.

I really only use five of the seven available homescreen panels, organising them to give me the quickest possible access to the information and applications I want most often.

The home homescreen panel

On the central or 'home' panel, I have widgets showing forthcoming appointments in my Google calendar (Touch Calendar), my task/to-do list (Astrid), and the weather (standard HTC). At the top of the page is a toolbar (Extended Controls) that allows me to turn on and off WiFi, ringtone and screen auto-orientation, to change screen brightness, and to turn on the LED torch. Finally, at the bottom-right of the screen are icons for the clock and the camera (both standard HTC).

The right-hand panels

The three panels to the right are where I organise my most often-used widgets and icons. On the first (on the left in the image above) you'll see at the top the green Evernote widget. Evernote is an indispensable cross-platform note-taking and document management tool, about which I'll probably say more later. At the bottom is the widget of my podcast app, Pocket Casts. Between the two widgets are the icons of eight essential apps. From left to right and top to bottom, these are:

• web browser (Dolphin Browser HD)
• RSS newsreader (NewsRob)
• web clippings storage (Read It Later Pro)
• email (Gmail)
• French dictionary (Larousse)
• e-book reader (FBReader)
• Google Maps
• contact list (standard HTC)

The second screen on the right also has two widgets - those of the Twitter app, Tweetdeck, and the default Android music player, which I prefer to the standard HTC one. Down the side are the icons for the Android Market app, Dropbox (sign up for Dropbox here) and Google Docs.

The last screen on the right houses less-often used tools. Maybe I'll get to some of them later.

The left-hand panels

To the left of the central panel I store only the widgets of the standard HTC SMS app and a calculator (also HTC). I don't use the left-most panel at all.

There you have it - that's the top layer of my mobile computing environment. In the future, I'll go below the surface to show you how some of these tools work.

Next post: Sync without trace